I have the same problem, and even more…
A lot of things are not working well actually. Not only the widgets. Sometimes I get a blank page for no reason.
The Dashboard page stays for 2 seconds and then blank page…
The visitor side of the blog is kind of having some problem too. There is a slideshow and now for 1 or 2 seconds you can see all pictures.
I tried all possible fix.
I installed a new wordpress on the same “website”, and I have a blank page straight after the login.
The thing is that it happened like that.