Hm. There is W502 Empty FINALLY block.

Please try the latest build http://sourceoddity.com/download/FixInsight_2015.11upd4_setup.exe

It works fine with your demo. At least for me :)

It should work fine, command line process doesn't use any shared resources.

In a normal situation it can only return 0,1 or 2 exit code. I guess 255 means that it has been interrupted by some OS exception.

Can you please turn on Debug Mode (a check box in about dialog) and send me a log after a fail?

This would be great, do a simple demo please.

By the way, FixInsight's settings are per-project. So what's the point of moving them to Tools->Options... ?