upgrade 19.04 to 19.10 - problem with repo - cannot upgrade

[Christian Machado]

After type "update-manager"
On stage "setting new software channels"
This error is returned:

"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'."

But there are no repositories unofficials.

ProblemType: Bug
DistroRelease: Ubuntu 19.04
Package: ubuntu-release-upgrader-core 1:19.04.16.9
ProcVersionSignature: Ubuntu 5.0.0-40.44-generic 5.0.21
Uname: Linux 5.0.0-40-generic x86_64
ApportVersion: 2.20.10-0ubuntu27.4
Architecture: amd64
CrashDB: ubuntu
CurrentDesktop: XFCE
Date: Sat Feb 15 22:30:45 2020
InstallationDate: Installed on 2019-07-15 (216 days ago)
InstallationMedia: Xubuntu 19.04 "Disco Dingo" - Release amd64 (20190416)
PackageArchitecture: all
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: Upgraded to disco on 2020-02-16 (0 days ago)
VarLogDistupgradeTermlog:

[Juhani Numminen (jsonic)]

Could you try again, but before the upgrade, disable disco-proposed by adding a # character in the last line of /etc/apt/sources.list.

(Reason for my recommendation: The log files show problems with libc6 and libudev1, which have different versions in eoan-proposed than eoan.)