Can't save move or edit widgets

Very strange. I was notified by my customer that all of a sudden we can’t move, edit, save, or add anything in the widgets area. I have disabled and removed any new plugins but that hasn’t had any effect on this.

I’ve never seen this before. When I go to save a widget, it takes a few seconds then the widget disappears and the home page appears in the widget area.

I’ve scanned the site and it appears clean so I don’t think it’s malware anywhere…

Please help.