If phpMyAdmin is displaying an error or inaccessible and you cannot find another reason for this, it may be that some of the configuration files are corrupted. In that case, it's best to reinstall the phpMyAdmin RPM.
To reinstall phpMyAdmin, you would run the following two commands:
rpm -e --nodeps cpanel-phpmyadmin
These above-provided commands will remove the cpanel-phpMyAdmin RPM and then reinstall it.