I don't think having packages from both Nvidia-340 and Nvidia-460 installed at the same time is supported. Please uninstall or purge the packages from whichever version you don't need.
** Changed in: nvidia-graphics-drivers-340 (Ubuntu) Status: New => Invalid -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to nvidia-graphics-drivers-340 in Ubuntu. https://bugs.launchpad.net/bugs/1911998 Title: package nvidia-340 (not installed) failed to install/upgrade: trying to overwrite '/lib/udev/rules.d/71-nvidia.rules', which is also in package nvidia-kernel-common-460 460.32.03-0ubuntu0.20.04.1 Status in nvidia-graphics-drivers-340 package in Ubuntu: Invalid Bug description: mmm ProblemType: Package DistroRelease: Ubuntu 20.04 Package: nvidia-340 (not installed) ProcVersionSignature: Ubuntu 5.8.0-38.43~20.04.1-generic 5.8.18 Uname: Linux 5.8.0-38-generic x86_64 NonfreeKernelModules: nvidia_modeset nvidia ApportVersion: 2.20.11-0ubuntu27.14 Architecture: amd64 CasperMD5CheckResult: skip Date: Fri Jan 15 19:39:33 2021 ErrorMessage: trying to overwrite '/lib/udev/rules.d/71-nvidia.rules', which is also in package nvidia-kernel-common-460 460.32.03-0ubuntu0.20.04.1 InstallationDate: Installed on 2021-01-14 (0 days ago) InstallationMedia: Ubuntu 20.04.1 LTS "Focal Fossa" - Release amd64 (20200731) Python3Details: /usr/bin/python3.8, Python 3.8.5, python3-minimal, 3.8.2-0ubuntu2 PythonDetails: N/A RelatedPackageVersions: dpkg 1.19.7ubuntu3 apt 2.0.2ubuntu0.2 SourcePackage: nvidia-graphics-drivers-340 Title: package nvidia-340 (not installed) failed to install/upgrade: trying to overwrite '/lib/udev/rules.d/71-nvidia.rules', which is also in package nvidia-kernel-common-460 460.32.03-0ubuntu0.20.04.1 UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/nvidia-graphics-drivers-340/+bug/1911998/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp