https://bugs.winehq.org/show_bug.cgi?id=49802
--- Comment #2 from Reinhold reinhold.hoffmann@hotmail.com --- Thanks for the immediate response. It is very helpful.
With the discussion on stackoverflow (https://stackoverflow.com/questions/53244454/how-did-wine64-manage-to-handle...) the issue is now clearly understood.
Our task now is to find a workaround either - use CreateThread instead of AfxBeginThread because our apps use AfxBeginThread just in few cases, or - stay longer with VS2010
In the future this issue may become a major obstacle because more developments - migrate their apps to x64 - use of latest Visual Studio versions - use Wine primarily for macOS because of the greater prevalence of Mac PCs compared to Linux PCs
I hope that the report here helps others, too.
Thanks again.