Ubuntu software is not working, upgraded from 15 to 16.04 LTS

I upgraded my Ubuntu today to 16.04 LTS, everything went fine. But somehow Ubuntu software is not working. by not working I mean:

• The windows opens and I see the Transmission app as featured
• I go to other Tabs and nothing is shown
• I search for an app and it just keeps spinning without showing any error msg or any result
• I've checked and I have a working internet connection
• I don't know how to debug or reinstall it