error updating ubuntu to version 19.10

[Evgeniy Potorochin]

when trying to upgrade from ubuntu version 18.04.4 to version 19.10, an error occurs
Failed to calculate system update. An unsolvable problem occurred while calculating updates. This was probably due to: * Unofficial software packages not supported by Ubuntu Please use the 'ppa-purge' command from the ppa-purge package to remove the software from Launchpad PPA and try updating again.
I tried various solutions, but nothing worked and the error still appears.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: ubuntu-release-upgrader-core 1:18.04.37
ProcVersionSignature: Ubuntu 5.3.0-62.56~18.04.1-generic 5.3.18
Uname: Linux 5.3.0-62-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.15
Architecture: amd64
CrashDB: ubuntu
CurrentDesktop: ubuntu:GNOME
Date: Wed Jul 8 13:56:11 2020
InstallationDate: Installed on 2019-09-14 (298 days ago)
InstallationMedia: Ubuntu 18.04.2 LTS "Bionic Beaver" - Release amd64 (20190210)
PackageArchitecture: all
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=ru_RU.UTF-8
 SHELL=/bin/bash
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: Upgraded to bionic on 2020-07-08 (0 days ago)
VarLogDistupgradeTermlog:

mtime.conffile..etc.update-manager.release-upgrades: 2019-10-19T16:49:38.839176

[Daniel Letzeisen (dtl131)]

It looks like you still have this PPA active: https://launchpad.net/~oibaf/+archive/ubuntu/graphics-drivers

You should purge it according to instructions:

=== Revert to original drivers ===
To revert to standard Ubuntu drivers type the following in a prompt shell:
$ sudo apt-get install ppa-purge
$ sudo ppa-purge ppa:oibaf/graphics-drivers

Also, you have other foreign repositories that may cause issues and need to be disabled:
2020-07-08 13:51:45,289 DEBUG examining: 'deb [arch=amd64] https://download.docker.com/linux/ubuntu focal stable'
2020-07-08 13:51:45,290 DEBUG entry '# deb [arch=amd64] https://download.docker.com/linux/ubuntu focal stable # заблокировано при обновлении до eoan' was disabled (unknown mirror)
2020-07-08 13:51:45,290 DEBUG examining: 'deb https://download.sublimetext.com/ apt/stable/'
2020-07-08 13:51:45,291 DEBUG entry '# deb https://download.sublimetext.com/ apt/stable/ # заблокировано при обновлении до eoan' was disabled (unknown mirror)
2020-07-08 13:51:45,293 DEBUG examining: 'deb [arch=amd64] http://dl.google.com/linux/chrome/deb/ stable main'
2020-07-08 13:51:45,294 DEBUG entry '# deb [arch=amd64] http://dl.google.com/linux/chrome/deb/ stable main # заблокировано при обновлении до eoan' was disabled (unknown mirror)

Please try the upgrade again after taking care of foreign sources and post updated logs.

[Launchpad Janitor (janitor)]

[Expired for ubuntu-release-upgrader (Ubuntu) because there has been no activity for 60 days.]