Cache can not be client

When cleaning the cache the following error appears:

Call to undefined function RegularLabs\Plugin\System\CacheCleaner\Cache\shell_exec()

Using the latst Joomla! 3 (3.10.11) and Cache Cleaner Pro extension
PHP 8.1.17

yes that fixed it! I was unable to disable it in the plugin settings, because saving it invokes cache cleaner and since it was broken it errored out. I ended up removing the extension and installing it again. Maybe it is an idea to disable the automatic clean when saving the cache cleaner plugin itself? That might prevent a "locked out" situation.