startx fails to start
remove Xauthority THEN :
alt + ctrl + F1 THEN :
sudo pkill -9 Xorg THEN:
startx
hope this helps
Try to remove your .Xauthority file:
sudo rm /home/florian/.Xauthority
And restart your system (with your normal user account)
Fixed this problem with:
sudo chmod 1777 /tmp /var/tmp