diff --git a/src/gui_2.py b/src/gui_2.py
index ff6a3d93..0c4d96bb 100644
--- a/src/gui_2.py
+++ b/src/gui_2.py
@@ -727,7 +727,7 @@ class App:
     err = run_result.errors[0]
     if hasattr(self, "controller") and self.controller is not None:
      self.controller._gui_degraded_reason = err.message
-     self.controller._last_imgui_assert = traceback.format_exception(type(err.original), err.original, err.original.__traceback__) if err.original else ""
+     self.controller._last_imgui_assert = str(err.original) if err.original else err.message
     if not hasattr(self, '_startup_timeline_errors'): self._startup_timeline_errors = []
     self._startup_timeline_errors.append(("run.immapp", err))
     return