Erel, text editor can't open the bas file. Any other way?Check the source files with a text editor. One of them is corrupted. Hopefully it is the meta file which you can delete.
Get the backup and replace the file. Looks like the file is damaged.
That´s bad.
I do a complete Backup of my PC every Night using a Backupmedium (RDX-Drive). Think over a Backupsolution for your PC.
Last year i lost a HDD due to a HDD-Crash. I lost all my Sources from a few years because i did not backup...
NOW i have this RDX-Solution.