An unresolvable problem occurred while calculating the upgrade. This was caused by: * Upgrading to a pre-release version of Ubuntu This is most likely a transient problem, please try again later. 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'.

[Muhammad Amin Ghazi]

An unresolvable problem occurred while calculating the upgrade.

 This was caused by:
 * Upgrading to a pre-release version of Ubuntu
This is most likely a transient problem,
please try again later.
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 20.10
Package: ubuntu-release-upgrader-core 1:20.10.15
ProcVersionSignature: Ubuntu 5.8.0-50.56-generic 5.8.18
Uname: Linux 5.8.0-50-generic x86_64
ApportVersion: 2.20.11-0ubuntu50.5
Architecture: amd64
CasperMD5CheckResult: skip
CrashDB: ubuntu
CurrentDesktop: ubuntu:GNOME
Date: Sun May 2 20:31:53 2021
InstallationDate: Installed on 2021-01-17 (104 days ago)
InstallationMedia: Ubuntu 20.04.1 LTS "Focal Fossa" - Release amd64 (20200731)
PackageArchitecture: all
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: Upgraded to groovy on 2021-05-02 (0 days ago)
VarLogDistupgradeTermlog: