You say the error is inconsistent and happens after some 15-20 times? My first inclination would be some form of race condition that causes garbage collection to fail because the memory is still in use somewhere else. That would be consistent with the inconsistencies you are seeing with the errors. In that case, check for module/memory access and make sure it is thread safe.
A memory leak through Active bar 2 is another possibility. Reference:
Active Bar 2 (Actbar2.ocx) leaks memory - Our ComponentOne - Our ComponentOne
The other possibility is a set of variables that are created but never assigned to, resulting in random behavior when the memory is freed because sometimes the values are well defined and other times they are not. That scenario may be more difficult to track down, especially if it is occurring within the Active bar 2 extension.
You could also try different display drivers per the first link you provided. Are you suspecting some conflict with the UI and display adapter drivers?
Yes it is proprietary. (I tried to quote but may have got it wrong. I am not used to forums a lot)
the strange thing is its not re-creatable on every server. In some instances we got the application installed locally (win 7) and the users stop getting the errors.
We commented out Tbr.RecalcLayout since that seemed to be where it was crashing but it started crashing at other places. some users are more affected than others even though they connect to the same server(some dont get it at all). We have rebuilt user profiles, re-installed the app, toggled with permissions etc. but no use.
Its more of an issue on Windows 2012 R2 (only one instance discovered recently of the server being 2008 R2 but that is also not confirmed since we found that desktop experience is not enabled and that does cause some issues + on that server we are getting the crash every time). In a lot of instances we have been notified that the issues started after upgrading to 2012 R2 - which gives more credibility to our observation.
I will look at the link to see if that helps.
Thanks for your reply and assistance. If you can think of something else or any further assistance would be immensely appreciated !!