I am upgrading from Ubuntu 19.04 to 19.10 and getting this error message: Could not calculate the upgrade An unresolvable problem occurred while calculating the upgrade.

[Alireza Alikhani]

I am not a programmer and just need simple fix to the problem. thanks

ProblemType: Bug
DistroRelease: Ubuntu 19.04
Package: ubuntu-release-upgrader-core 1:19.04.16.9
ProcVersionSignature: Ubuntu 5.3.0-26.28~18.04.1-generic 5.3.13
Uname: Linux 5.3.0-26-generic x86_64
ApportVersion: 2.20.10-0ubuntu27.4
Architecture: amd64
CrashDB: ubuntu
CurrentDesktop: ubuntu:GNOME
Date: Sun Feb 16 10:27:40 2020
InstallationDate: Installed on 2019-03-15 (337 days ago)
InstallationMedia: Ubuntu 18.04.2 LTS "Bionic Beaver" - Release amd64 (20190210)
PackageArchitecture: all
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: Upgraded to disco on 2020-02-16 (0 days ago)
VarLogDistupgradeTermlog:

mtime.conffile..etc.update-manager.release-upgrades: 2020-02-15T14:26:45.368733