Mysterious lockscreen that does not work

[xkonti]

Hello. My RPi is connected via WiFi bundle and that is usually the only peripheral i connect to it. It was working great so far with SSL and VNC but today suddenly VNC does not work. To look what is going on I connected RPi to HDMI display. My eyes saw that screen:



I can choose: Default Xsession, LXDE, Openbox.
Whatever i choose and log in (standard pi and raspberry) screen goes black for a while and then returns to the lockscreen. I'm beginner with linux so i have no idea what to do :/

Any ideas how to get past it and disable it? I have access to console and files via SSH.