If I launch minecraft, I can't see anything (see screenshot in attachments).

Error Log:

[1223/180139:INFO:LauncherAppBrowser.cpp(24)] Work dir is /home/tobi/.minecraft

[1223/180139:INFO:ClientHandler.cpp(182)] Creating launcher window.

[1223/180140:WARNING:mainLinux.cpp(25)] X error received: type 0, serial 297, error_code 8, request_code 42, minor_code 0

[1223/180142:INFO:LauncherAppRenderer.cpp(110)] Javascript bridge extended.

[1223/180144:ERROR:sandbox_linux.cc(343)] InitializeSandbox() called with multiple threads in process gpu-process.
[1223/180145:INFO:ClientHandler.cpp(859)] Preferences / startup: Read preferences

[1223/180145:INFO:ClientHandler.cpp(859)] Preferences: Wrote preferences

[1223/180145:INFO:ClientHandler.cpp(859)] Configurations: Loading profiles

[1223/180145:INFO:ClientHandler.cpp(859)] Configurations: Loading settings

[1223/180145:INFO:ClientHandler.cpp(859)] Configurations: defaulting to first configuration, because we couldn't find one by ID null

[1223/180145:INFO:ClientHandler.cpp(859)] Session: Read authDB

[1223/180145:INFO:ClientHandler.cpp(859)] Updating server status

[1223/180145:INFO:GameController.cpp(233)] Reinstancing game callbacks...

[1223/180146:INFO:ClientHandler.cpp(859)] Preferences: Wrote preferences

[1223/180146:INFO:ClientHandler.cpp(859)] GameStarter: Previous instance(s) found

[1223/180247:WARNING:mainLinux.cpp(25)] X error received: type 0, serial 805, error_code 3, request_code 15, minor_code 0

[1223/180326:WARNING:x11_util.cc(1404)] X error received: serial 384, error_code 185 (GLXBadWindow), request_code 155, minor_code 32 (X_GLXDestroyWindow)
[1223/180328:INFO:ClientHandler.cpp(149)] Shutting down!

[1223/180330:WARNING:x11_util.cc(1404)] X error received: serial 387, error_code 3 (BadWindow (invalid Window parameter)), request_code 4, minor_code 0 (X_DestroyWindow)