Alright I "fixed" it by manually playing around with the permissions of res_mods, but on every new install it still reverts to being broken and I have to change it manually again.
You might want to check how the installer sets permissions for some files, basically, playing on a regular user account and having to provide the admin pw in order to run the installer, it will seemingly randomly set permissions for some of the files installed which means that WoT running on the regular account doesn't have access.