I am using Wolfram Mathematica 12.1 and the Wolfram System Modeler 12.1 on a Windows 10 (64 Bit) notebook. Pretty much exactly since yesterday (2020-04-10), I am experiencing severe and previously unknown issues with running models in System Modeler and Mathematica.

Minimum Example

(* "12.1.0 for Microsoft Windows (64-bit) (March 14, 2020)" *)

] // Head


We should of course have gotten SystemModelSimulationData. During the evaluation the following error messages are given:

SystemModelSimulate::bld : Failed to build model DocumentationExamples.Simulation.WeakAxis.

SystemModelSimulate::bldI : Internal error: Stack overflow

I am getting the internal error message also for validating elementary classes in WSM 12.1 and when trying to run introductory example models in WSM 12.1 Simulation Center.

Is anybody else experiencing these errors? Since over the easter break I will not be able to reach WRI or MathCore: Have you found a fix? (Maybe a Windows 10 update is the culprit here?)


I tested on a separate Windows computer using my home license and there the example worked. So it seems that one can narrow down this issue to cases, where WSM and Mathematica are installed on the same machine. This predominantly appears to be a Wolfram System Modeler issue.

  • 1
    $\begingroup$ No problem in Linux, using Version 12.1. $\endgroup$ – Rolf Mertig Apr 11 at 9:36
  • $\begingroup$ @Rolf Could you possibly clarify: Are there no problems in both, WSM and Mma, in Linux? $\endgroup$ – gwr Apr 11 at 9:44
  • $\begingroup$ Works fine on macOS 10.15.4 with MMA V12.1 (I don't have WSM). $\endgroup$ – imas145 Apr 11 at 11:00
  • 1
    $\begingroup$ Can you try unloading all models that are not shipped with SystemModeler and try again? Maybe some other model is interfering with all model builds somehow. $\endgroup$ – Malte Lenz Apr 12 at 17:05
  • 1
    $\begingroup$ @gwr yes, it is certainly a bug in System Modeler then. If you can narrow down which model is causing the issue (or are willing to share all of them), feel free to send them to me, and I will make sure the bug is fixed. $\endgroup$ – Malte Lenz Apr 12 at 18:13

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.