I haven't downgraded so I don't know.
It worked fine in the last version though
This seems to be an error that crops up every second or third update
Usually I just put up with it until the next update which generally fixes the problem

Thanks for your report. So if you downgrade back to 6.6.1, does it start working again?

If I manually drag and drop files it works fine but if I use 'Keep remote directory up to date' I get abnormal program termination and the program crashes

This started with the last update 6.6.2 RC