I have running timers and threads when I quit. Could this be the reason for this assertion? I am using 603-dev2 on Windows.
Very likely - if you have threads running at exit. Actually, at the moment, it seems to me like bad practice - IMO code process should start and end with single thread...
Unfortunately, it is also quite possible that this fails with MT app even if ended as one thread - TiminigInspector has very specic use and is not MT safe (and likely will never be).
The real question is: are you using TIMING or RTIMING macros somewhere or they are just forgoten in U++ library code?