when i upgrade from version 18.04 to 20.04, an unsolvable problem occurred while calculating the progress, and the upgrade crashes

[Riccardo]

when i upgrade from version 18.04 to 20.04, an unsolvable problem occurred while calculating the progress, and the upgrade crashes

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: ubuntu-release-upgrader-core 1:18.04.44
ProcVersionSignature: Ubuntu 4.15.0-144.148-generic 4.15.18
Uname: Linux 4.15.0-144-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.9-0ubuntu7.24
Architecture: amd64
CrashDB: ubuntu
CurrentDesktop: ubuntu:GNOME
Date: Sun Jun 6 18:57:22 2021
InstallationDate: Installed on 2018-01-29 (1223 days ago)
InstallationMedia: Ubuntu 16.04.3 LTS "Xenial Xerus" - Release amd64 (20170801)
PackageArchitecture: all
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=it_IT.UTF-8
 SHELL=/bin/bash
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: Upgraded to bionic on 2021-06-06 (0 days ago)
VarLogDistupgradeTermlog:

[Chris Guiver (guiverc)]

Thank you for taking the time to report this bug and helping to make Ubuntu better.

I see a number of 3rd party packages, esp. from https://launchpad.net/~oibaf/+ppa-packages

For best results with a release-upgrade, you should remove all 3rd party packages (bringing your system back to a pure Ubuntu one, ie. no 3rd party packages) then perform the upgrade. The tool ppa-purge can assist with this.

Likely related to https://bugs.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/+bug/1069133

(following from https://bugs.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/+bug/1922546/comments/2)

[The use of oibaf ppa] will prevent the upgrade as that PPA contains package version numbers greater than the release to which you are upgrading. You can revert the PPA by installing the ppa-purge package from the official Ubuntu archive and then running 'sudo ppa-purge ppa:oibaf/graphics-drivers'. After that you can try upgrading again and if it still fails open a new bug report. Thanks and good luck!