pycharm not launching on ubuntu 16

 Hello,

My pycharm community edition stopped working all of a sudden. When I launch it from the terminal, I get the screen allowing to create a new project or use an existing one, but whichever I choose, I only get the 'ttip of the day' screen and then nothing opens : I only get the bar on the top of my screen noting that I am supposedly using the application, but I get no starting menu, nothing..

It would seem like the problem started after I tried to install qt , but I don't know how to work this round.

Would anybody have a suggestion on how to fix this?

Thanking you in advance,

M