That is not a good sign if multiple files went to 0 bytes.
I would suspect that something happened on the server at the same time and your setting was a fluke.
But anyway.
Good thing you had backups of most of the important files needed.
The control panel files are probably wiped also.
That should be a easy fix.
re upload the files in forum/admin.
You can use a virgin copy unless you have modified the stock version.
