Attaching full stacktrace herewith:

What views were opened or data loaded? Or was it an empty workbench?

Closing an empty workbench or loaded workbench using X button on the title bar causes this.

I tried running the Workbench on Linux both with valgrind as well as AdressSanitizer. Unfortunately there is a lot of noise from memory leaks and stuff, but I did not spot anything obvious which could be the cause.

I think the first entry point to debug this manually would be:

8   libITKCommon-4.13.1.dylib     	0x0000000106e3f9bd itk::Object::UnRegister() const + 109
9   libMitkCore.dylib             	0x00000001058d11a7 itk::SmartPointer<itk::BoundingBox<unsigned long, 3, double, itk::VectorContainer<unsigned long, itk::Point<double, 3u> > > const>::~SmartPointer() + 23

So basically trying to identify itk::BoundingBox cleanup locations through smart pointers which are a direct or indirect member of static objects.

Update:
Problem is cannot be replicated anymore on my mac book (after a restart). Only Happens recurrently at certain times.