I've played the game normally for the past few years but today I attempted to subscribe to some of the modded zombies maps in the workshop. I have uninstalled 3 times and attempted to verify the game cache several times.
I have also unsubscribed and uninstalled all the maps from the SteamApps folder.
Tried searching around online for a few hours with no luck following what others say to do.

Please help, much appreciated.