Upgrade fail from gui and terminal

[Victor]

Try to upgrade from 18.04 to 20.04 from gui and terminal.
Both don't works for me.
Disable custom repositories doesn't help.

Error on upgrade:

Checking package manager
Reading package lists... Done
Building dependency tree
Reading state information... Done

Calculating the changes

Calculating the changes

Could not calculate the upgrade

An unresolvable problem occurred while calculating the upgrade.

If none of this applies, then please report this bug using the
command 'ubuntu-bug ubuntu-release-upgrader-core' in a terminal. If
you want to investigate this yourself the log files in
'/var/log/dist-upgrade' will contain details about the upgrade.
Specifically, look at 'main.log' and 'apt.log'.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: ubuntu-release-upgrader-core 1:18.04.40
ProcVersionSignature: Ubuntu 4.15.0-123.126-generic 4.15.18
Uname: Linux 4.15.0-123-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.9-0ubuntu7.20
Architecture: amd64
CrashDB: ubuntu
CurrentDesktop: ubuntu:GNOME
Date: Sat Nov 14 19:26:12 2020
InstallationDate: Installed on 2018-08-17 (819 days ago)
InstallationMedia: Ubuntu 18.04.1 LTS "Bionic Beaver" - Release amd64 (20180725)
PackageArchitecture: all
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: Upgraded to bionic on 2020-11-13 (0 days ago)

[Victor (victor82)]

Removing all PPA packages and repositories doesn't help.
Fixed by myself by changing main repo to focal and full-upgrade.