diff --git a/core/src/create.jl b/core/src/create.jl
index a76d7259f..b9ab781c8 100644
--- a/core/src/create.jl
+++ b/core/src/create.jl
@@ -704,13 +704,21 @@ function User(db::DB, config::Config)::User
             first_row = time[first_row_idx]
             is_active = true
         else
-            @error "User node #$node_id data not in any table."
+            @error "User node $node_id data not in any table."
             errors = true
         end
 
-        if !all(all.(>(0), eachcol(interpolations)))
-            error("Demand should be a non-negative number")
+        for (col, id) in zip(interpolations, node_ids)
+            for (demand_p_itp, p_itp) in zip(col, priorities)
+                if any(demand_p_itp.u .< 0.0)
+                    @error "Demand of user node $id with priority #$p_itp should be non-negative"
+                    errors = true
+                end
+            end
         end
+        #if !all(all.(>=(0.0), eachcol(interpolations)))
+        #    error("Demand should be a non-negative number")
+        #end
 
         if !isnothing(first_row)
             min_level_ = coalesce(first_row.min_level, 0.0)