Alertezs. I do not understand why the activation of the plugin caused a critical error?
Everything is working fine on my site.
There are some problems on your site, perhaps some incompatibility with another plugin.
Remove the plugin - you need to clean the site cache.
Optimize the Database.
Install the addon plugin again.
If the error persists, disable all plugins and install the addon. Then activate all disabled plugins in turn.
This is the only way to determine which plugin is the problem.
Everything is working fine on my site.
There are some problems on your site, perhaps some incompatibility with another plugin.
Remove the plugin - you need to clean the site cache.
Optimize the Database.
Install the addon plugin again.
If the error persists, disable all plugins and install the addon. Then activate all disabled plugins in turn.
This is the only way to determine which plugin is the problem.