Symptoms
After uninstalling CloudLinux, the uninstaller may leave some packages behind due to compatibility or dependency reasons. This is stated as well by the uninstaller:
Also some CloudLinux packages weren't removed automatically,
because it can lead to the problems with excludes, dependencies, protected packages
or something else.
You can find the remained packages using the command
rpm -qa --queryformat '%{name}-%{version}-%{release} %{vendor}\n' | grep CloudLinux
And manually downgrade them to upstream packages if ones exist in the upstream repositories
or remove them if packages exist only in the CloudLinux repositories.
Description
The conflict may manifest itself during a cPanel update and will show similar failures in the log:
[2020-10-16 05:50:27 +0000] W Error: Multilib version problems found. This often means that the root
[2020-10-16 05:50:27 +0000] W Error: Protected multilib versions: libgomp-4.8.5-39.el7.i686 != libgomp-4.8.5-39.el7.cloudlinux.x86_64
[2020-10-16 05:50:27 +0000] W Error: Protected multilib versions: libstdc++-4.8.5-39.el7.i686 != libstdc++-4.8.5-39.el7.cloudlinux.x86_64
[2020-10-16 05:50:27 +0000] W Error: Protected multilib versions: libgcc-4.8.5-39.el7.i686 != libgcc-4.8.5-39.el7.cloudlinux.x86_64
These conflicts are presented due to the fact the packages mentioned in the failure are provided by CloudLinux, which is no longer installed.
Workaround
To resolve these failures, the packages simply need to be downgraded via YUM to install their CentOS-provided counterparts.
Using the packages from the log example above, we would run the following command:
yum downgrade libgomp libstdc++* libgcc