Lightroom doesn't work after latest update due to connection error

After installing the latest version of lightroom, it worked perfectly. But after rebooting my laptop (and therefor, closing lightroom) I can't use it no more. 

Lightroom doesn't show me my pics no more although I can see the album "all pics and see the number" it just doesn't let me access it. I also can't see my manually added albums. 

After some time I got this notification :

login server error "connection error" error with registration PUT operation timed out after 300893 milliseconds with 0 out 0 bytes received

What do I do?

I don't want to lose my catalog.. 

Photoshop still works though. 

And I have enough space on my laptop.