How can I fix my black social event bar

@DancingXRaven  Try removing any mod that affects the user interface, for example the UI Cheats mod.  Delete localthumbcache.package as well.

If that doesn't help or you don't have a UI mod, move your entire Mods folder to the desktop, delete localthumbcache (again), and test.  If the problem is gone, you can add your mods and cc back a few files at a time and see when the problem recurs.  You'll then know that the cause is one of the files you just added, and you can narrow it down from there.