Commented Unassigned: Release 14 Conversion Failure [1796]

I upgraded from Release 12 which had been working well for a couple of months to Release 14. Now getting FFmpeg errors. Using Windows 7 64-bit. Log file attached.

I'm not sure what to try. Any help is much appreciated.
Comments: ** Comment from web user: golf28king **

Tried to log in. My username and password don't let me in.