When I log in, It says: Can not connect to server.

When I log in (with e-mail and password) on the launcher, it says: cannot connect to server. It doesn't open the game. When I open the launcher with an other Windows Session where my account is already connected, it opens the game but I can't go online. Can you plz help me? I tried to deinstall and reinstall my game but the launcher always says: Can not connect to server.