Can't find media library

Hi, after a recent upgrade to WordPress 4.2 I can’t find my media library anymore in WordPress admin. Images won’t upload to it either, they show up after you click upload but then I can’t find them again.

When I try to write a post and click the add media button, nothing happens.

I can see the folders arranged in year and month via FTP, but can’t see anything in them. But the images do show in live blog posts from the last few years, so they must be somewhere…

I read a few related posts here and tried changing permissions for the uploads directory to 777 but nothing changed.

Any suggestions appreciated! Many thanks

Scott