Error message when closing the app

In a few apps I have CalendarPro . When I close the application this error shows:


It happens when Capesoft Office Inside and/or Capesoft Filexplorer is also in the app
ever seen this ? I have to make a small demo app to figure out which one causes it.
(Calendar Pro 4.06 - codejock 18.4) but it happens in older versions too.
When I do not open the Calendar and close the app all is fine (no error)

OK, made a small demoapp; added CalendarPro to it - compile: ok
Then added CS Office Inside: - compile ok; close app: nor error
Then added CS Fileexplorer: - compile ok: close app: no error
Added CD Draw: all fine
Conclusion: I do not know - will test further