diff --git a/OMPython/ModelicaSystem.py b/OMPython/ModelicaSystem.py
index 59efe177..29c5b48b 100644
--- a/OMPython/ModelicaSystem.py
+++ b/OMPython/ModelicaSystem.py
@@ -1145,15 +1145,15 @@ def simulate(
         cmd_definition = om_cmd.definition()
         returncode = self._session.run_model_executable(cmd_run_data=cmd_definition)
         # and check returncode *AND* resultfile
-        if returncode != 0 and self._result_file.is_file():
+        if returncode != 0:
             # check for an empty (=> 0B) result file which indicates a crash of the model executable
             # see: https://github.com/OpenModelica/OMPython/issues/261
             #      https://github.com/OpenModelica/OpenModelica/issues/13829
-            if self._result_file.size() == 0:
+            if self._result_file.is_file() and self._result_file.size() == 0:
                 self._result_file.unlink()
                 raise ModelicaSystemError("Empty result file - this indicates a crash of the model executable!")
 
-            logger.warning(f"Return code = {returncode} but result file exists!")
+            logger.warning(f"Return code = {returncode} but result file was created!")
 
         self._simulated = True
 
@@ -2144,9 +2144,9 @@ def worker(worker_id, task_queue):
                 try:
                     returncode = self.get_session().run_model_executable(cmd_run_data=cmd_definition)
                     logger.info(f"[Worker {worker_id}] Simulation {resultpath.name} "
-                                f"finished with return code: {returncode}")
-                except ModelicaSystemError as ex:
-                    logger.warning(f"Simulation error for {resultpath.name}: {ex}")
+                                f"finished with return code {returncode}")
+                except OMCSessionException as ex:
+                    logger.warning(f"Error executing {repr(cmd_definition.get_cmd())}: {ex}")
 
                 # Mark the task as done
                 task_queue.task_done()
diff --git a/OMPython/OMCSession.py b/OMPython/OMCSession.py
index 861f2a3a..9efbc879 100644
--- a/OMPython/OMCSession.py
+++ b/OMPython/OMCSession.py
@@ -800,20 +800,23 @@ def run_model_executable(cmd_run_data: OMCSessionRunData) -> int:
                 env=my_env,
                 cwd=cmd_run_data.cmd_cwd_local,
                 timeout=cmd_run_data.cmd_timeout,
-                check=True,
+                check=False,
             )
             stdout = cmdres.stdout.strip()
             stderr = cmdres.stderr.strip()
             returncode = cmdres.returncode
 
-            logger.debug("OM output for command %s:\n%s", repr(cmdl), stdout)
+            if returncode != 0:
+                logger.warning("OM executable run %s with returncode=%d and stdout:\n%s",
+                               repr(cmdl), returncode, stdout)
+            else:
+                logger.debug("OM executable run %s with stdout:\n%s", repr(cmdl), stdout)
 
             if stderr:
                 raise OMCSessionException(f"Error running model executable {repr(cmdl)}: {stderr}")
+
         except subprocess.TimeoutExpired as ex:
             raise OMCSessionException(f"Timeout running model executable {repr(cmdl)}") from ex
-        except subprocess.CalledProcessError as ex:
-            raise OMCSessionException(f"Error running model executable {repr(cmdl)}") from ex
 
         return returncode