f runner fix only if exists

t3/runners/rmg_runner.py

@@ -331,7 +331,7 @@ def rmg_runner(rmg_input_file_path: str,
                       and not(len(rmg_errors) >= 2 and error is not None and error == rmg_errors[-2])
             restart_rmg = False if error is not None and 'Could not find one or more of the required files/directories ' \
                                                          'for restarting from a seed mechanism' in error else True
-        if fix_cantera_model:
+        if fix_cantera_model and os.path.isfile(rmg_input_file_path):
             fix_cantera_model_files(rmg_path=os.path.dirname(rmg_input_file_path))
         return not converged
     else: