You should go ahead and delete everything in your custom folder and download Tori and Uke in-game.
Check every folder's permissions (i.e. Data, Custom, Extra Content) if you have full control on that. There are several cases that it shows you have full control but its only for the administrator and in-case you're logged in as another account than administrator then you might have partial control. You might have to go in advanced settings and do everything which is done on the page shared above (Surge's link).

If nothing is working then the problem is not with permissions and your TB is broken itself.
Should try reinstalling Toribash or Steam.

Edit: How about you install Toribash on a different Hard drive. If It's in C:, try installing in D: or vice versa.