Multiple WordPress problems

Recently, actually from 2 days ago, all sites on the server that are WordPress based are acting really weird. Dashboard drop down menu isn’t working. When trying to execute orders the pages are blank. The sites pages are blank from some people. Sometime they get 403 Error. Theme footer and sidebar doesn’t load on any theme. Widget menu is broken. Plugins can’t be updated because it says it can’t create directory.
I really need help because multiple sites are affected by these issues.