I am running v 10.2.0.0 (but I had the same issue with v 10.1.0.0) on Windows 7 x64. I happened to view an old TXT file containing a single Windows bullet character (0x95) as a thumbnail. It crashed Directory Opus with:
The error 0xC0000005 occurred in thread 'dopus.thumbgenerate' at address 0x000007FEE8FB6DC7.
After tracing the problem down to this file, I tried recreating the text file from scratch with the same character in a newly created TXT file and it again crashed. This problem does not occur on Windows XP x32 and it does not occur on Windows 7 x64 if the character in the TXT file is a period instead of a bullet. I no longer need this little file and have deleted it to prevent further problems, but thought I would pass this information on.
...Jim