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On Ubuntu 16.04 after a recent apt-get upgrade, X login is not working. Why?
The login screen (which I understand is X-based) is working. However all attempts to login, including via the guest account fail. When I switch to a text terminal and look at .xsession-errors, I see:
X Error of failed request: BadValue (integer parameter out of range for operation)
Major opcode of failed request: 154 (GLX)
Minor opcode of failed request: 3 (X_GLXCreateContext)
Value in failed request: 0x0
Serial number of failed request: 34
Current serial number in output stream: 35
The Xserver being used is NVIDIA, however it seems like this must be an Ubuntu login issue as X itself appears to be working and /var/log/Xorg.0.log is uninformative (everything looks fine). Any ideas how to debug further?