The plugin package of Fast Social Share that is installed doesn't match your actual Joomla version and is not fully compatible. The package for Joomla 3.x is currently installed but you are running Joomla 4.x, if you have just upgraded your Joomla website from the version 3.x to the version 4.x the plugin must also be upgraded accordingly.To upgrade the plugin, visit our store at https://storejextensions.org, download the package for Joomla 4.x and install it over the current one