In a big model, the program crashes when you try to run any Python-script or add-In.
Visum 11.5 is affected by an error in the memory management of the component wxPython that may cause an crash for really big version files (> 1 GB). In Visum 12, this is corrected with a new version of wxPython. Workaround: 1) Start Visum. 2) Run any add-In (i.e. Python console) and close it again. 3) Load the version file. 4) Run the add-In's.