The driver install failed. You would need to locate the driver installer log to discover why that is. Also it looks like you had a previous driver installed from Ubuntu sources (nvidia-driver-XYZ) and you are now attempting to run the runfile installer. That is not recommended, please read the CUDA linux install guide carefully.
It didn’t work for me even in front of the server, so I had to solve this bug installing through “Ubuntu Advanced mode”:
$ reboot
then: F8
then: Advanced options for Ubuntu
then: Ubuntu… (recovery mode)
then: root Drop to root shell prompt
then: (in command line):
$ sudo sh cuda_11.0.3_450.51.06_linux.run
$ reboot
It seems the installer is not able to install when you have previous installations for graphics (even Nouveau). So the solution is as easy as loading the operative system in recovery mode.