diff --git a/CHANGELOG b/CHANGELOG
index 73511b19ec..0dfd5ef49c 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -185,20 +185,14 @@ Miscellaneous
 Fixed bugs
 ----------
 
-- skip constraint propagation if the residual activity bound cancels the side precision in tightenVarBounds() of cons_linear.c
-- use indices of negation counterparts and accept fixings when ordering and-resultants of pseudoboolean constraints
+- skip linear constraint propagation if the residual activity bound cancels the side precision
 - correct bound tracking to make the evaluation of primal-dual-integrals work
-- update locks on model variables before removing pseudoboolean constraints in consPresolPseudoboolean()
 - skip aggregations on fixed variables in milp presolver to avoid errors for earlier versions of PaPILO
+- use indices of negation counterparts and accept fixings when ordering and-resultants of pseudoboolean constraints
+- update locks on model variables before removing pseudoboolean constraints in presolve
 - reformulate soft pseudoboolean constraints with linear constraints if the indicator decomposition is disabled
-- in lpi_highs set the presolve option in lpiSolve() to not reset the model status directly after solving the LP
-- update constraints and hashmap after each multi-aggregation to avoid key error in removeDoubleAndSingletonsAndPerformDualpresolve() of cons_setppc.c
-
-Unit tests
-----------
-
-Testing
--------
+- add workaround for recent HiGHS versions resetting the model status when changing the presolve option after a solve
+- avoid hashmap key error in removal of doubletons and singletons in dual presolve of setppc constraints by updating constraints and corresponding hashmaps after each multi-aggregation
 
 Build system
 ------------
@@ -207,16 +201,11 @@ Build system
 
 - attempted to fix detection of CPLEX library on macOS and Windows systems
 
-### Makefile
-
 Miscellaneous
 -------------
 
 - adjusted Gurobi interface for Gurobi 12
 
-Known bugs
-----------
-
 @section RN911 SCIP 9.1.1
 *************************
 
diff --git a/applications/Scheduler/src/cons_optcumulative.c b/applications/Scheduler/src/cons_optcumulative.c
index 3fe2555dc3..2be91f49fd 100644
--- a/applications/Scheduler/src/cons_optcumulative.c
+++ b/applications/Scheduler/src/cons_optcumulative.c
@@ -1146,13 +1146,6 @@ SCIP_RETCODE addRelaxation(
 
    consdata->relaxadded = TRUE;
 
-#if 0
-   if( !conshdlrdata->rowrelax )
-   {
-      SCIP_CALL( SCIPrestartSolve(scip) );
-   }
-#endif
-
    return SCIP_OKAY;
 }
 
@@ -1877,75 +1870,6 @@ SCIP_RETCODE enfopsCons(
    return SCIP_OKAY;
 }
 
-#if 0
-/** enforce the LP or pseudo solution */
-static
-SCIP_RETCODE enfoCons(
-   SCIP*                 scip,               /**< SCIP data structure */
-   SCIP_CONS*            cons,               /**< constraint to be checked */
-   SCIP_Bool*            violated,           /**< pointer to store if the constraint is violated */
-   SCIP_Bool*            rowadded            /**< pointer to store if a row was added */
-   )
-{
-   SCIP_CONSDATA* consdata;
-   SCIP_VAR** binvars;
-   SCIP_VAR** vars;
-   int* demands;
-   int* durations;
-   SCIP_Bool auxiliary;
-   SCIP_Bool cutoff;
-   int nvars;
-
-   assert(scip != NULL);
-   assert(cons != NULL);
-   assert(violated != NULL);
-
-   SCIPdebugMessage("check optcumulative constraints <%s>\n", SCIPconsGetName(cons));
-
-   consdata = SCIPconsGetData(cons);
-   assert(consdata != NULL);
-
-   SCIP_CALL( SCIPallocBufferArray(scip, &binvars, consdata->nvars) );
-   SCIP_CALL( SCIPallocBufferArray(scip, &vars, consdata->nvars) );
-   SCIP_CALL( SCIPallocBufferArray(scip, &durations, consdata->nvars) );
-   SCIP_CALL( SCIPallocBufferArray(scip, &demands, consdata->nvars) );
-
-   /* collect information of all activities which are assigned to that machine in the given solution */
-   collectSolActivities(scip, consdata, NULL, binvars, vars, durations, demands, &nvars, &auxiliary);
-
-   if( nvars > 0 )
-   {
-      /* check the cumulative condition */
-      SCIP_CALL( SCIPcheckCumulativeCondition(scip, NULL, nvars, vars,
-            durations, demands, consdata->capacity, consdata->hmin, consdata->hmax, violated, cons, FALSE) );
-
-      if( *violated )
-      {
-#if 0
-         /* create row */
-         SCIP_CALL( createRow(scip, SCIPconsGetName(cons), binvars, vars, durations, demands, nvars,
-               consdata->capacity, TRUE, &cutoff) );
-#endif
-         /* reset constraint age since it successfully detected infeasibility */
-         SCIP_CALL( SCIPresetConsAge(scip, cons) );
-      }
-      else
-      {
-         /* increase constraint age since it did not detected infeasibility */
-         SCIP_CALL( SCIPincConsAge(scip, cons) );
-      }
-   }
-
-   /* free all buffers */
-   SCIPfreeBufferArray(scip, &demands);
-   SCIPfreeBufferArray(scip, &durations);
-   SCIPfreeBufferArray(scip, &vars);
-   SCIPfreeBufferArray(scip, &binvars);
-
-   return SCIP_OKAY;
-}
-#endif
-
 /** upgrade constraints to an cumulative constraint */
 static
 SCIP_RETCODE upgradeCons(
diff --git a/applications/Scheduler/src/heur_optcumulative.c b/applications/Scheduler/src/heur_optcumulative.c
index 4e39e6ccb2..cbd495fcf8 100644
--- a/applications/Scheduler/src/heur_optcumulative.c
+++ b/applications/Scheduler/src/heur_optcumulative.c
@@ -253,9 +253,6 @@ SCIP_RETCODE applyOptcumulative(
    SCIP_Real upperbound;
    SCIP_Real pseudoobj;
    SCIP_Bool infeasible;
-#if 0
-   int depth;
-#endif
 
    assert(heur != NULL);
    assert(heurdata != NULL);
@@ -264,9 +261,6 @@ SCIP_RETCODE applyOptcumulative(
    infeasible = FALSE;
 
    *result = SCIP_DIDNOTFIND;
-#if 0
-   depth = SCIPgetDepth(scip);
-#endif
 
    /* start probing */
    SCIP_CALL( SCIPstartProbing(scip) );
@@ -545,29 +539,6 @@ SCIP_RETCODE applyOptcumulative(
          if( stored )
             *result = SCIP_FOUNDSOL;
       }
-#if 0
-      else
-      {
-         /* check that code */
-         int v;
-
-         SCIP_CALL( SCIPinitConflictAnalysis(scip) );
-
-         for( v = 0; v < heurdata->machines[m]; ++v )
-         {
-            SCIP_CALL( SCIPaddConflictBinvar(scip, heurdata->binvars[m][v]) );
-            SCIP_CALL( SCIPaddConflictLb(scip, heurdata->vars[m][v], NULL) );
-            SCIP_CALL( SCIPaddConflictUb(scip, heurdata->vars[m][v], NULL) );
-         }
-
-         /* analyze the conflict */
-#if 0
-         SCIP_CALL( SCIPanalyzeConflict(scip, depth, NULL) );
-#endif
-         SCIP_CALL( SCIPanalyzeConflict(scip, 0, NULL) );
-         SCIP_CALL( SCIPfreeSol(scip, &sol) );
-      }
-#endif
    }
 
    /* exit probing mode */
diff --git a/src/scip/cons_cumulative.c b/src/scip/cons_cumulative.c
index 27447ac89b..861c07e63c 100644
--- a/src/scip/cons_cumulative.c
+++ b/src/scip/cons_cumulative.c
@@ -410,7 +410,8 @@ SCIP_RETCODE computeImpliedEst(
    int*                  est                 /**< pointer to store the implied earliest start time */
    )
 {  /*lint --e{715}*/
-#if 0
+#ifdef SCIP_DISABLED_CODE
+   /* there is a bug below */
    SCIP_VAR** vbdvars;
    SCIP_VAR* vbdvar;
    SCIP_Real* vbdcoefs;
@@ -422,7 +423,7 @@ SCIP_RETCODE computeImpliedEst(
 
    (*est) = SCIPconvertRealToInt(scip, SCIPvarGetLbLocal(var));
 
-#if 0
+#ifdef SCIP_DISABLED_CODE
    /* the code contains a bug; we need to check if an implication forces that the jobs do not run in parallel */
 
    nvbdvars = SCIPvarGetNVlbs(var);
@@ -479,7 +480,8 @@ SCIP_RETCODE computeImpliedLct(
    int*                  lct                 /**< pointer to store the implied latest completion time */
    )
 {  /*lint --e{715}*/
-#if 0
+#ifdef SCIP_DISABLED_CODE
+   /* there is a bug below */
    SCIP_VAR** vbdvars;
    SCIP_VAR* vbdvar;
    SCIP_Real* vbdcoefs;
@@ -490,7 +492,7 @@ SCIP_RETCODE computeImpliedLct(
 
    (*lct) = SCIPconvertRealToInt(scip, SCIPvarGetUbLocal(var)) + duration;
 
-#if 0
+#ifdef SCIP_DISABLED_CODE
    /* the code contains a bug; we need to check if an implication forces that the jobs do not run in parallel */
 
    nvbdvars = SCIPvarGetNVubs(var);
@@ -1442,7 +1444,9 @@ SCIP_DECL_SOLVECUMULATIVE(solveCumulativeViaScipCp)
    return SCIP_OKAY;
 }
 
-#if 0
+#ifdef SCIP_DISABLED_CODE
+/* The following code should work, but is currently not used. */
+
 /** solve single cumulative condition using SCIP and the time indexed formulation */
 static
 SCIP_DECL_SOLVECUMULATIVE(solveCumulativeViaScipMip)
@@ -2736,112 +2740,6 @@ SCIP_RETCODE resolvePropagationCoretimes(
    return SCIP_OKAY;
 }
 
-#if 0
-/** repropagation of edge finding algorithm simplified version from Petr Vilim only a small subset is reported such that
- *  energy in total and for bound change is enough
- */
-static
-SCIP_RETCODE resolvePropagationEdgeFinding(
-   SCIP*                 scip,               /**< SCIP data structure */
-   int                   nvars,              /**< number of start time variables (activities) */
-   SCIP_VAR**            vars,               /**< array of start time variables */
-   int*                  durations,          /**< array of durations */
-   int                   hmin,               /**< left bound of time axis to be considered (including hmin) */
-   int                   hmax,               /**< right bound of time axis to be considered (not including hmax) */
-   SCIP_VAR*             infervar,           /**< variable whose bound change is to be explained */
-   INFERINFO             inferinfo,          /**< inference info containing position of correct bdchgids */
-   SCIP_BOUNDTYPE        boundtype,          /**< the type of the changed bound (lower or upper bound) */
-   SCIP_BDCHGIDX*        bdchgidx,           /**< the index of the bound change, representing the point of time where the change took place */
-   SCIP_Bool             usebdwidening,      /**< should bound widening be used during conflict analysis? */
-   SCIP_Bool*            explanation         /**< bool array which marks the variable which are part of the explanation if a cutoff was detected, or NULL */
-   )
-{
-   int est;
-   int lct;
-   int j;
-
-   /* ???????????????????? do bound widening */
-
-   assert(scip != NULL);
-   assert(nvars > 0);
-   assert(inferInfoGetProprule(inferinfo) == PROPRULE_2_EDGEFINDING);
-
-   SCIPdebugMsg(scip, "repropagate edge-finding with short reasons for variable <%s>\n", SCIPvarGetName(infervar));
-
-   if( boundtype == SCIP_BOUNDTYPE_LOWER )
-   {
-      SCIP_CALL( SCIPaddConflictLb(scip, infervar, bdchgidx) );
-   }
-   else
-   {
-      SCIP_CALL( SCIPaddConflictUb(scip, infervar, bdchgidx) );
-   }
-
-   est = inferInfoGetData1(inferinfo);
-   lct = inferInfoGetData2(inferinfo);
-   assert(est < lct);
-
-   /* collect the energies of all variables in [est_omega, lct_omega] */
-   for( j = 0; j < nvars; ++j )
-   {
-      SCIP_VAR* var;
-      SCIP_Bool left;
-      SCIP_Bool right;
-      int duration;
-      int lb;
-      int ub;
-
-      var = vars[j];
-      assert(var != NULL);
-
-      if( var == infervar )
-      {
-         if( explanation != NULL )
-            explanation[j] = TRUE;
-
-         continue;
-      }
-
-      lb = SCIPconvertRealToInt(scip, SCIPgetVarLbAtIndex(scip, var, bdchgidx, FALSE));
-      ub = SCIPconvertRealToInt(scip, SCIPgetVarUbAtIndex(scip, var, bdchgidx, FALSE));
-
-      duration = durations[j];
-      assert(duration > 0);
-
-      /* in case the earliest start time is equal to hmin we have to also consider the jobs which run in that region
-       * since we use adjusted jobs during the propagation
-       */
-      left = (est == hmin && lb + duration > hmin) || lb >= est;
-
-      /* in case the latest completion time is equal to hmax we have to also consider the jobs which run in that region
-       * since we use adjusted jobs during the propagation
-       */
-      right = (lct == hmax && ub < hmax) || ub + duration <= lct;
-
-      /* store all jobs running in [est_omega; lct_omega] */
-      if( left && right  )
-      {
-         /* check if bound widening should be used */
-         if( usebdwidening )
-         {
-            SCIP_CALL( SCIPaddConflictRelaxedLb(scip, var, bdchgidx, (SCIP_Real)(lct - duration)) );
-            SCIP_CALL( SCIPaddConflictRelaxedUb(scip, var, bdchgidx, (SCIP_Real)(est)) );
-         }
-         else
-         {
-            SCIP_CALL( SCIPaddConflictLb(scip, var, bdchgidx) );
-            SCIP_CALL( SCIPaddConflictUb(scip, var, bdchgidx) );
-         }
-
-         if( explanation != NULL )
-            explanation[j] = TRUE;
-      }
-   }
-
-   return SCIP_OKAY;
-}
-#endif
-
 /** compute the minimum overlaps w.r.t. the duration of the job and the time window [begin,end) */
 static
 int computeOverlap(
@@ -10901,7 +10799,9 @@ SCIP_RETCODE tightenCoefs(
    return SCIP_OKAY;
 }
 
-#if 0
+#ifdef SCIP_DISABLED_CODE
+/* The following should work, but does not seem to be tested well. */
+
 /** try to reformulate constraint by replacing certain jobs */
 static
 SCIP_RETCODE reformulateCons(
@@ -11084,9 +10984,6 @@ SCIP_RETCODE presolveCons(
    SCIP_CONSHDLRDATA*    conshdlrdata,       /**< constraint handler data */
    SCIP_PRESOLTIMING     presoltiming,       /**< timing of presolving call */
    int*                  nfixedvars,         /**< pointer to store the number of fixed variables */
-#if 0
-   int*                  naggrvars,          /**< pointer to counter which is increased by the number of deduced variable aggregations */
-#endif
    int*                  nchgbds,            /**< pointer to store the number of changed bounds */
    int*                  ndelconss,          /**< pointer to store the number of deleted constraints */
    int*                  naddconss,          /**< pointer to store the number of added constraints */
@@ -11154,7 +11051,8 @@ SCIP_RETCODE presolveCons(
 
    assert(checkDemands(scip, cons) || *cutoff);
 
-#if 0
+#ifdef SCIP_DISABLED_CODE
+   /* The following should work, but does not seem to be tested well. */
    SCIP_CALL( reformulateCons(scip, cons, naggrvars) );
 #endif
 
@@ -11261,30 +11159,6 @@ TCLIQUE_NEWSOL(tcliqueNewsolClique)
    SCIPdebugMessage("####### max clique %d\n", cliqueweight);
 }
 
-/** print the tclique graph */
-#if 0
-static
-void tcliquePrint(
-   SCIP*                 scip,               /**< SCIP data structure */
-   TCLIQUE_GRAPH*        tcliquegraph        /**< tclique graph */
-   )
-{
-   int nnodes;
-   int i;
-   int j;
-
-   nnodes = tcliquegraph->nnodes;
-
-   for( i = 0; i < nnodes; ++i )
-   {
-      for( j = 0; j < nnodes; ++j )
-      {
-         SCIPinfoMessage(scip, NULL, "(%d/%d) ", tcliquegraph->precedencematrix[i][j], tcliquegraph->demandmatrix[i][j]);
-      }
-      SCIPinfoMessage(scip, NULL, "\n");
-   }
-}
-#endif
 
 /** @} */
 
@@ -11818,14 +11692,6 @@ SCIP_RETCODE findCumulativeConss(
          demandrow[c] = tcliquegraph->demandmatrix[v][c];
          demandcol[c] = tcliquegraph->demandmatrix[c][v];
 
-#if 0
-         if( precedencerow[c] || precedencecol[c] )
-         {
-            tcliquegraph->demandmatrix[v][c] = FALSE;
-            tcliquegraph->demandmatrix[c][v] = FALSE;
-         }
-#endif
-
          tcliquegraph->precedencematrix[c][v] = FALSE;
          tcliquegraph->precedencematrix[v][c] = FALSE;
       }
@@ -12735,7 +12601,7 @@ SCIP_DECL_CONSEXITPRE(consExitpreCumulative)
    {
       SCIP_CALL( evaluateCumulativeness(scip, conss[c]) );
 
-#if 0
+#ifdef SCIP_DISABLED_CODE
       SCIP_CALL( SCIPvisualizeConsCumulative(scip, conss[c]) );
 #endif
    }
@@ -13094,9 +12960,6 @@ SCIP_DECL_CONSPROP(consPropCumulative)
    int nchgbds;
    int ndelconss;
    int c;
-#if 0
-   int naggrvars = 0;
-#endif
 
    SCIPdebugMsg(scip, "propagate %d of %d useful cumulative constraints\n", nusefulconss, nconss);
 
@@ -13123,13 +12986,9 @@ SCIP_DECL_CONSPROP(consPropCumulative)
 
       if( SCIPgetDepth(scip) == 0 )
       {
-#if 0
-         SCIP_CALL( presolveCons(scip, cons, conshdlrdata, SCIP_PRESOLTIMING_ALWAYS,
-               &nchgbds, &naggrvars, &nchgbds, &ndelconss, &nchgbds, &nchgbds, &nchgbds, &cutoff, &cutoff) );
-#else
          SCIP_CALL( presolveCons(scip, cons, conshdlrdata, SCIP_PRESOLTIMING_ALWAYS,
                &nchgbds, &nchgbds, &ndelconss, &nchgbds, &nchgbds, &nchgbds, &cutoff, &cutoff) );
-#endif
+
          if( cutoff )
             break;
 
@@ -13149,13 +13008,6 @@ SCIP_DECL_CONSPROP(consPropCumulative)
       }
    }
 
-#if 0
-   if( !cutoff && conshdlrdata->dualpresolve && SCIPallowStrongDualReds(scip) && nconss > 1 )
-   {
-      SCIP_CALL( propagateAllConss(scip, conss, nconss, TRUE, &nchgbds, &cutoff, NULL) );
-   }
-#endif
-
    if( cutoff )
    {
       SCIPdebugMsg(scip, "detected infeasible\n");
@@ -13223,13 +13075,8 @@ SCIP_DECL_CONSPRESOL(consPresolCumulative)
 
       if( presoltiming != SCIP_PRESOLTIMING_MEDIUM )
       {
-#if 0
-         SCIP_CALL( presolveCons(scip, cons, conshdlrdata, presoltiming,
-               nfixedvars, naggrvars, nchgbds, ndelconss, naddconss, nchgcoefs, nchgsides, &cutoff, &unbounded) );
-#else
          SCIP_CALL( presolveCons(scip, cons, conshdlrdata, presoltiming,
                nfixedvars, nchgbds, ndelconss, naddconss, nchgcoefs, nchgsides, &cutoff, &unbounded) );
-#endif
 
          if( cutoff || unbounded )
             break;
@@ -14297,7 +14144,8 @@ SCIP_RETCODE SCIPvisualizeConsCumulative(
          }
       }
 
-#if 0
+#ifdef SCIP_MORE_OUTPUT
+      /* define to also output variable bounds */
       vbdvars = SCIPvarGetVubVars(var);
       nvbdvars = SCIPvarGetNVubs(var);
 
diff --git a/src/scip/cons_linear.c b/src/scip/cons_linear.c
index ad016457e7..6078f06637 100644
--- a/src/scip/cons_linear.c
+++ b/src/scip/cons_linear.c
@@ -8465,7 +8465,8 @@ SCIP_RETCODE extractCliques(
 
             i = nposbinvars + nnegbinvars - 1;
             j = i - 1;
-#if 0 /* assertion should only holds when constraints were fully propagated and boundstightened */
+#ifdef SCIP_DISABLED_CODE
+            /* assertion should only hold when constraints were fully propagated and boundstightened */
             /* check that it is possible to choose binvar[i], otherwise it should have been fixed to zero */
             assert(SCIPisFeasGE(scip, binvarvals[i], threshold));
 #endif
@@ -8625,7 +8626,8 @@ SCIP_RETCODE extractCliques(
             i = nposbinvars + nnegbinvars - 1;
             j = i - 1;
 
-#if 0 /* assertion should only holds when constraints were fully propagated and boundstightened */
+#ifdef SCIP_DISABLED_CODE
+            /* assertion should only hold when constraints were fully propagated and boundstightened */
             /* check if the variable should not have already been fixed to one */
             assert(!SCIPisFeasGT(scip, binvarvals[i], threshold));
 #endif
@@ -8784,7 +8786,8 @@ SCIP_RETCODE extractCliques(
 
             j = 1;
 
-#if 0 /* assertion should only holds when constraints were fully propagated and boundstightened */
+#ifdef SCIP_DISABLED_CODE
+            /* assertion should only hold when constraints were fully propagated and boundstightened */
             /* check if the variable should not have already been fixed to one */
             assert(!SCIPisFeasLT(scip, -binvarvals[0], threshold));
 #endif
diff --git a/src/scip/cons_linking.c b/src/scip/cons_linking.c
index 0ee080052e..d870c01848 100644
--- a/src/scip/cons_linking.c
+++ b/src/scip/cons_linking.c
@@ -1551,7 +1551,9 @@ SCIP_Bool checkCons(
    return SCIPisFeasEQ(scip, linksum, linkvarval) && SCIPisFeasEQ(scip, setpartsum, 1.0);
 }
 
-#if 0
+#ifdef SCIP_DISABLED_CODE
+/* The following should work, but does not seem to be tested well. */
+
 /** transfer aggregated integer variables to the corresponding binary variables */
 static
 SCIP_RETCODE aggregateVariables(
@@ -2919,9 +2921,10 @@ SCIP_DECL_CONSPRESOL(consPresolLinking)
       }
    }
 
-#if 0
+#ifdef SCIP_DISABLED_CODE
+   /* The following should work, but does not seem to be tested well. */
+
    /* transfer aggregated linking variables to the corresponding binary variables */
-   assert(conshdlrdata->varmap != NULL);
    SCIP_CALL( aggregateVariables(scip, conshdlrdata->varmap, conss, nconss, naggrvars, &cutoff) );
 #endif
 
@@ -3178,7 +3181,8 @@ SCIP_DECL_CONSDEACTIVE(consDeactiveLinking)
 static
 SCIP_DECL_CONSENABLE(consEnableLinking)
 {  /*lint --e{715}*/
-#if 0
+#ifdef SCIP_DISABLED_CODE
+   /** @todo The following might help, but it would need to be tested whether it speeds up the solution process. */
    SCIP_CONSHDLRDATA* conshdlrdata;
    SCIP_CONSDATA* consdata;
 
diff --git a/src/scip/cons_xor.c b/src/scip/cons_xor.c
index a2eb3f9a31..a9979f1512 100644
--- a/src/scip/cons_xor.c
+++ b/src/scip/cons_xor.c
@@ -3464,7 +3464,8 @@ SCIP_RETCODE cliquePresolve(
    if( !consdata->deleteintvar )
       return SCIP_OKAY;
 
-#if 0 /* try to evaluate if clique presolving should only be done multiple times when the constraint changed */
+#ifdef SCIP_DISABLED_CODE
+   /* try to evaluate if clique presolving should only be done multiple times when the constraint changed */
    if( !consdata->changed )
       return SCIP_OKAY;
 #endif
@@ -4468,10 +4469,8 @@ SCIP_RETCODE preprocessConstraintPairs(
             consdataSort(consdata0);
          assert(consdata0->sorted);
 
-#if 0
-      /* if aggregation in the core of SCIP is not changed we do not need to call applyFixing, this would be the correct
-       * way
-       */
+#ifdef SCIP_DISABLED_CODE
+      /* TODO: consider running applyFixings() on the persistent constraint to detect a cutoff */
       /* remove all variables that are fixed to zero and all pairs of variables fixed to one;
        * merge multiple entries of the same or negated variables
        */
diff --git a/src/scip/expr_product.c b/src/scip/expr_product.c
index 79fc3bec03..71486c509e 100644
--- a/src/scip/expr_product.c
+++ b/src/scip/expr_product.c
@@ -548,7 +548,8 @@ SCIP_RETCODE mergeProductExprlist(
          if( !issignpower1 && !issignpower2 )
          {
             /* and both are normal power, then add to unsimplifiedchildren the resulting expr of simplify(base^(expo1 + expo2)) */
-#if 0  /* TODO we should not loose the implicit base >= 0 constraint, if there is one, but then we should look at bounds on base; simplify currently doesn't */
+#ifdef SCIP_DISABLED_CODE
+            /* TODO we should not loose the implicit base >= 0 constraint, if there is one, but then we should look at bounds on base; simplify currently doesn't */
             /*
              * unless expo1 or expo2 are fractional but expo1+expo2 is not fractional, then we better keep the original
              * the reason for that is that x^fractional implies a constraint x >= 0
diff --git a/src/scip/heur_bound.c b/src/scip/heur_bound.c
index 4364504528..e7686f5a5f 100644
--- a/src/scip/heur_bound.c
+++ b/src/scip/heur_bound.c
@@ -168,24 +168,10 @@ SCIP_RETCODE applyBoundHeur(
          SCIP_CALL( SCIPpropagateProbing(scip, maxproprounds, &infeasible, NULL) );
       }
 
-      /* try to repair probing */
+      /* todo: try to backtrack */
+      /* stop if infeasible */
       if( infeasible )
-      {
-#if 0
-         SCIP_CALL( SCIPbacktrackProbing(scip, SCIPgetProbingDepth(scip) - 1) );
-
-         /* fix the last variable, which was fixed the reverse bound */
-         SCIP_CALL( SCIPfixVarProbing(scip, var, SCIPvarGetUbLocal(var)) );
-
-         /* propagate fixings */
-         SCIP_CALL( SCIPpropagateProbing(scip, maxproprounds, &infeasible, NULL) );
-
-         SCIPdebugMsg(scip, "backtracking ended with %sfeasible problem\n", (infeasible ? "in" : ""));
-
-         if( infeasible )
-#endif
-            break;
-      }
+         break;
    }
 
    SCIPdebugMsg(scip, "probing ended with %sfeasible problem\n", infeasible ? "in" : "");
diff --git a/src/scip/misc.c b/src/scip/misc.c
index 8af5b016b1..fb7ac7e2a6 100644
--- a/src/scip/misc.c
+++ b/src/scip/misc.c
@@ -8712,7 +8712,7 @@ void btnodeFreeLeaf(
    assert((*node)->left == NULL);
    assert((*node)->right == NULL);
 
-#if 0
+#ifdef SCIP_DISABLED_CODE
    /* remove reference from parent node */
    if( (*node)->parent != NULL )
    {
diff --git a/src/scip/nlhdlr_perspective.c b/src/scip/nlhdlr_perspective.c
index b6c993e7a4..ca087128ef 100644
--- a/src/scip/nlhdlr_perspective.c
+++ b/src/scip/nlhdlr_perspective.c
@@ -1241,7 +1241,6 @@ SCIP_DECL_NLHDLRFREEEXPRDATA(nlhdlrFreeExprDataPerspective)
    return SCIP_OKAY;
 }
 
-
 /** callback to be called in deinitialization */
 static
 SCIP_DECL_NLHDLREXIT(nlhdlrExitPerspective)
@@ -1487,7 +1486,6 @@ SCIP_DECL_NLHDLRINITSEPA(nlhdlrInitSepaPerspective)
    return SCIP_OKAY;
 }
 
-
 /** nonlinear handler enforcement callback
  *
  * "Perspectivies" cuts produced by other nonlinear handlers.
diff --git a/src/scip/presol_gateextraction.c b/src/scip/presol_gateextraction.c
index 25b5f42668..6a064522c1 100644
--- a/src/scip/presol_gateextraction.c
+++ b/src/scip/presol_gateextraction.c
@@ -1291,7 +1291,8 @@ SCIP_DECL_PRESOLEXEC(presolExecGateextraction)
 
    *result = SCIP_DIDNOTRUN;
 
-#if 0 /* need to include cons_knapsack on top of this file */
+#ifdef SCIP_DISABLED_CODE
+   /* need to include cons_knapsack on top of this file */
    /* check for possible knapsacks that form with a logicor a weak relaxation of an and-constraint
     *
     * the weak relaxation of an and-constraint looks like:
diff --git a/src/scip/presolve.c b/src/scip/presolve.c
index 5b72e6d009..79e961fa3b 100644
--- a/src/scip/presolve.c
+++ b/src/scip/presolve.c
@@ -1099,7 +1099,7 @@ SCIP_RETCODE SCIPshrinkDisjunctiveVarSet(
     */
    implbinvarsexist = (SCIPprobGetNImplBinVars(scip->transprob) > 0);
 
-#if 0
+#ifdef SCIP_DISABLED_CODE
    /* @todo do the cleanup here rather than before calling SCIPshrinkDisjunctiveVarSet()? */
    if( usebin )
    {
diff --git a/src/scip/primal.c b/src/scip/primal.c
index 55adf587e9..2bcfae18f2 100644
--- a/src/scip/primal.c
+++ b/src/scip/primal.c
@@ -699,7 +699,8 @@ SCIP_RETCODE primalAddSol(
 
    SCIPdebug( SCIP_CALL( SCIPsolPrint(sol, set, messagehdlr, stat, transprob, NULL, NULL, FALSE, FALSE) ) );
 
-#if 0 /* this is not a valid debug check, but can be used to track down numerical troubles */
+#ifdef SCIP_DISABLED_CODE
+   /* this is not a valid debug check, but can be used to track down numerical troubles */
 #ifndef NDEBUG
    /* check solution again completely
     * it fail for different reasons:
diff --git a/src/scip/prop_pseudoobj.c b/src/scip/prop_pseudoobj.c
index 103ff296a1..cb8b4796d1 100644
--- a/src/scip/prop_pseudoobj.c
+++ b/src/scip/prop_pseudoobj.c
@@ -282,13 +282,13 @@ SCIP_DECL_SORTPTRCOMP(varCompObj)
    assert(SCIPvarGetObj(var1) != 0.0);
    assert(SCIPvarGetObj(var2) != 0.0);
 
-   /* first criteria is the absolute value of objective coefficient */
+   /* first criterion is the absolute value of objective coefficient */
    if( REALABS(SCIPvarGetObj(var1)) < REALABS(SCIPvarGetObj(var2)) )
       return -1;
    else if( REALABS(SCIPvarGetObj(var1)) > REALABS(SCIPvarGetObj(var2)) )
       return +1;
 
-   /* second criteria the locks which indicate most effect */
+   /* second criterion the locks which indicate most effect */
    if( SCIPvarGetObj(var1) > 0.0 )
       locks1 = SCIPvarGetNLocksDownType(var1, SCIP_LOCKTYPE_MODEL);
    else
@@ -304,7 +304,7 @@ SCIP_DECL_SORTPTRCOMP(varCompObj)
    if( locks1 > locks2 )
       return 1;
 
-   /* third criteria the other locks */
+   /* third criterion the other locks */
    if( SCIPvarGetObj(var1) > 0.0 )
       locks1 = SCIPvarGetNLocksUpType(var1, SCIP_LOCKTYPE_MODEL);
    else
@@ -320,7 +320,7 @@ SCIP_DECL_SORTPTRCOMP(varCompObj)
    if( locks1 > locks2 )
       return 1;
 
-   /* forth criteria use the problem index */
+   /* forth criterion use the problem index */
    return SCIPvarCompare(var1, var2);
 }
 
@@ -2582,9 +2582,10 @@ SCIP_RETCODE propagateCutoffboundGlobally(
          return SCIP_OKAY;
    }
 
-#if 0 /* might fail, but is not a real error, still need to investigate */
+#ifdef SCIP_DISABLED_CODE
+   /* might fail, but is not a real error, still need to investigate */
 #ifndef NDEBUG
-   /* check that the abort criteria for the binary variables works */
+   /* check that the abort criterion for the binary variables works */
    for( ; v < nminactvars; ++v )
    {
       assert(cutoffbound - pseudoobjval >=  propdata->minactimpls[v]->maxobjchg);
@@ -2732,9 +2733,10 @@ SCIP_RETCODE propagateCutoffboundBinvars(
          return SCIP_OKAY;
    }
 
-#if 0 /* might fail, but is not a real error, still need to investigate */
+#ifdef SCIP_DISABLED_CODE
+   /* might fail, but is not a real error, still need to investigate */
 #ifndef NDEBUG
-   /* check that the abort criteria for the binary variables works */
+   /* check that the abort criterion for the binary variables works */
    for( ; v < nminactvars; ++v )
    {
       var = minactvars[v];
@@ -3336,7 +3338,7 @@ SCIP_RETCODE propagateLowerbound(
             nchgbds++;
          }
 
-         /* update globally fixed index if abort criteria was applied */
+         /* update globally fixed index if abort criterion was applied */
          propdata->maxactfirstnonfixed = v;
 
          /* check all binary variables which could potentially be fixed */
@@ -3363,9 +3365,10 @@ SCIP_RETCODE propagateLowerbound(
             }
          }
 
-#if 0 /* might fail, but is not a real error, still need to investigate */
+#ifdef SCIP_DISABLED_CODE
+         /* might fail, but is not a real error, still need to investigate */
 #ifndef NDEBUG
-         /* check that the abort criteria for the binary variables works */
+         /* check that the abort criterion for the binary variables works */
          for( ; v < nmaxactvars && !cutoff; ++v )
          {
             var = maxactvars[v];
diff --git a/src/scip/prop_rootredcost.c b/src/scip/prop_rootredcost.c
index 1740e10be9..ac6fe8210b 100644
--- a/src/scip/prop_rootredcost.c
+++ b/src/scip/prop_rootredcost.c
@@ -153,7 +153,7 @@ SCIP_DECL_SORTPTRCOMP(varCompRedcost)
    else if( key1 > key2 )
       return +1;
 
-   /* second criteria use the problem index
+   /* second criterion: use the problem index
     *
     * @note The problem index is unique. That means the resulting sorting is unique.
     */
@@ -391,7 +391,7 @@ SCIP_RETCODE propagateBinaryBestRootRedcost(
    assert(!(*cutoff));
 
    /* the binary variables are stored in the beginning of the variable array; these variables are sorted w.r.t. cutoff
-    * bound which would lead to a fixing; that give us an abort criteria (see below)
+    * bound which would lead to a fixing; that give us an abort criterion (see below)
     */
    redcostvars = propdata->redcostvars;
    assert(redcostvars != NULL);
@@ -485,12 +485,13 @@ SCIP_RETCODE propagateBinaryBestRootRedcost(
    /* store the index of the variable which is not globally fixed */
    propdata->glbfirstnonfixed = v;
 
-#if 0 /* due to numerics it might be that the abort criteria did not work correctly, because the sorting mechanism may
-       * have evaluated variables with a really small difference in their reduced cost values but with really huge
-       * lpobjval as the same
-       */
+#ifdef SCIP_DISABLED_CODE
+   /* Due to numerics it might be that the abort criterion did not work correctly, because the sorting mechanism may
+    * have evaluated variables with a really small difference in their reduced cost values but with really huge
+    * lpobjval as the same. Thus, we disable the check below for now.
+    */
 #ifndef NDEBUG
-   /* check that the abort criteria works; that means none of the remaining binary variables can be fixed */
+   /* check that the abort criterion works; that means none of the remaining binary variables can be fixed */
    for( ; v < propdata->nredcostbinvars && !(*cutoff); ++v )
    {
       SCIP_VAR* var;
diff --git a/src/scip/scip_solve.c b/src/scip/scip_solve.c
index bb746451c0..c91379d205 100644
--- a/src/scip/scip_solve.c
+++ b/src/scip/scip_solve.c
@@ -674,7 +674,7 @@ SCIP_RETCODE presolveRound(
    SCIP_EVENT event;
    SCIP_Bool aborted;
    SCIP_Bool lastranpresol;
-#if 0
+#ifdef SCIP_DISABLED_CODE
    int oldpresolstart = 0;
    int oldpropstart = 0;
    int oldconsstart = 0;
@@ -724,7 +724,7 @@ SCIP_RETCODE presolveRound(
       i = *presolstart;
       j = *propstart;
       k = *consstart;
-#if 0
+#ifdef SCIP_DISABLED_CODE
       oldpresolstart = i;
       oldpropstart = j;
       oldconsstart = k;
@@ -1079,7 +1079,7 @@ SCIP_RETCODE presolveRound(
             SCIP_CALL( presolveRound(scip, timing, unbounded, infeasible, lastround, presolstart, presolend,
                   propstart, propend, consstart, consend) );
          }
-#if 0
+#ifdef SCIP_DISABLED_CODE
          /* run remaining exhaustive presolvers (if we did not start from the beginning anyway) */
          else if( (oldpresolstart > 0 || oldpropstart > 0 || oldconsstart > 0) && presolend == scip->set->npresols
             && propend == scip->set->nprops && consend == scip->set->nconshdlrs )
diff --git a/src/scip/tree.c b/src/scip/tree.c
index 61841f1962..16b80ab137 100644
--- a/src/scip/tree.c
+++ b/src/scip/tree.c
@@ -2149,10 +2149,6 @@ SCIP_RETCODE SCIPnodeAddHoleinfer(
    SCIP_Bool*            added               /**< pointer to store whether the hole was added, or NULL */
    )
 {
-#if 0
-   SCIP_VAR* infervar;
-#endif
-
    assert(node != NULL);
    assert((SCIP_NODETYPE)node->nodetype == SCIP_NODETYPE_FOCUSNODE
       || (SCIP_NODETYPE)node->nodetype == SCIP_NODETYPE_PROBINGNODE
@@ -2195,10 +2191,6 @@ SCIP_RETCODE SCIPnodeAddHoleinfer(
       left, right, node->depth, SCIPvarGetName(var), SCIPvarGetLbLocal(var), SCIPvarGetUbLocal(var), infercons != NULL ? "cons" : "prop",
       infercons != NULL ? SCIPconsGetName(infercons) : (inferprop != NULL ? SCIPpropGetName(inferprop) : "-"), inferinfo);
 
-#if 0
-   /* remember variable as inference variable, and get corresponding active variable, bound and bound type */
-   infervar = var;
-#endif
    SCIP_CALL( SCIPvarGetProbvarHole(&var, &left, &right) );
 
    if( SCIPvarGetStatus(var) == SCIP_VARSTATUS_MULTAGGR )
diff --git a/src/scip/var.c b/src/scip/var.c
index 5154f93aca..f2ee119834 100644
--- a/src/scip/var.c
+++ b/src/scip/var.c
@@ -2710,7 +2710,7 @@ SCIP_RETCODE varFreeParents(
          parentvar->data.aggregate.var = NULL;
          break;
 
-#if 0
+#ifdef SCIP_DISABLED_CODE
       /* The following code is unclear: should the current variable be removed from its parents? */
       case SCIP_VARSTATUS_MULTAGGR:
          assert(parentvar->data.multaggr.vars != NULL);
@@ -13558,7 +13558,7 @@ SCIP_Real SCIPvarGetImplRedcost(
                int probindex = SCIPvarGetProbindex(clqvar) + 1;
                assert(0 < probindex && probindex < nentries);
 
-#if 0
+#ifdef SCIP_DISABLED_CODE
                /* check that the variable was not yet visited or does not appear with two contradicting implications, ->
                 * can appear since there is no guarantee that all these infeasible bounds were found
                 */