Could not calculate the upgrade An unresolvable problem occurred while calculating the upgrade. This was likely caused by: Unofficial software packages not provided by Ubuntu

[Cora]

Could not calculate the upgrade An unresolvable problem occurred while calculating the upgrade.
This was likely caused by:
Unofficial software packages not provided by Ubuntu Please use the tool 'ppa-purge'from the ppa-purge package to remove software from a Launchpad PPA and try the upgrade again.
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 16.04
Package: ubuntu-release-upgrader-core 1:16.04.32
ProcVersionSignature: Ubuntu 4.4.0-210.242-generic 4.4.262
Uname: Linux 4.4.0-210-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.30
Architecture: amd64
CrashDB: ubuntu
Date: Tue May 30 03:26:49 2023
InstallationDate: Installed on 2018-10-17 (1685 days ago)
InstallationMedia: Ubuntu-Server 16.04.5 LTS "Xenial Xerus" - Release amd64 (20180731)
PackageArchitecture: all
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: Upgraded to xenial on 2023-05-30 (0 days ago)
mtime.conffile..etc.update-manager.release-upgrades: 2023-05-30T02:28:39.353402

[Cora (coraaaa)]

sudo add-apt-repository --remove ppa:ondrej/php

remove the ppa:ondrej/php,but also failed to upgrade and report the same fault