If this is what I think it is, a lot of us had this problem. This may be the solution, copied from one of the comments in the download page:
At this point since you installed a lot of the mod partially, re-doing it at this point would probably just be a bad idea since even if this fix works, it would be best to probably reinstall the game and start from scratch.
1. Find the changes.ini from the tslpatchdata folder
2. Open it with a notepad or some other text editor.
3. Go to "Edit", then "Replace All" and Replace / marks with \ marks and then change marks \ to / only in the date and the N/A line.
For everyone having problems with installing it with TSL Patcher, just do this and you should be set.