Mods Not Activating

Since the last update on the 28th of February, I have noticed that my Mods are not enabling despite doing so within the game itself. I have currently removed all of my mods, updated essential mods (UI Cheats, More Columns, & MC Command Center), reinstalled my game, repaired my game, and still nothing. It's as if I hadn't enabled custom content and mods. I'm not sure what else to do. Any help/suggestions would be greatly appreciated. Thanks in advance!