I very often get a crash in the autofocus routine. So last night I ran KStars in the VS debugger (KStars built locally from source). The crash was a stack overflow, in FITSData::trace(). The call stack was an endless list of FITSData::trace calling itself recursively. This happens quite often, unfortunately. This is on Win10 64-bit.
I was frustrated that it kept happening on the first clear night in months, so I did not get any other debugging info (no logs, etc.). Sorry about that. If the above is not enough of a hint to figure out the problem, I can get more data on the next clear night (who knows when).
Unless, of course, I can replicate the problem in daylight (possible, not tried). I will try to replicate it during the day to gather more debugging info, and to try to come up with an easily reproduceable test case.