My workaround after receiving the same error was to run:
dpkg -i -force-overwrite /var/cache/apt/archives/nvidia-390_390.30-0ubuntu1_amd64.deb
After that, the install succeeds and I haven't noticed any resulting issues.
My workaround after receiving the same error was to run:
dpkg -i -force-overwrite /var/cache/ apt/archives/ nvidia- 390_390. 30-0ubuntu1_ amd64.deb
After that, the install succeeds and I haven't noticed any resulting issues.