I believe that I have found the source of the problem. I looked at the Windows Application Event Log and found the following related to the error I have described:
Faulting application name: PixInsight.exe, version: 1.8.0.963, time stamp: 0x51007c04
Faulting module name: McPvNs.dll, version: 3.1.116.0, time stamp: 0x506df6c1
Exception code: 0xc0000005
Fault offset: 0x00000000002df152
Faulting process id: 0xe9c
Faulting application start time: 0x01ce0e38cf1642f7
Faulting application path: C:\Program Files\PixInsight\bin\PixInsight.exe
Faulting module path: C:\Program Files\McAfee\MAT\McPvNs.dll
McPvNs.dll is related to the McAfee vault feature that is installed by default with McAfee total protection.
I worked with McAfee support through chat (they were VERY helpful, I am quite impressed with their customer service) and removed (well, uninstalled and reinstalled without) the vault component. I have not been able to re-create the error. So in ITIL-speak, I have a work-around but the problem still remains.
I wonder if there is some sort of a timing issue where the McAfee component gives a delayed response to PI that is not handled? Or that McAfee doesn't work well in a fully multi-threaded application?
I am still willing to help debug as needed. From my standpoint, the incident is closed and this is a known error as long as it doesn't happen again.
Thanks,
--Andy