Also, look in your hosting services documentation or ask them directly how to properly “disable error reporting” on the hosting service.

Specifically, you want the display_errors setting in PHP to be turned off. The proper way to do this can vary from hosting to hosting. On some you may need to make a php.ini file, on others they will give you a line to add to .htaccess.

Nevertheless, this setting should *never* be enabled on a live site, and yet it is almost always enabled by default. Turn it off and the “Warning” messages will go away.

@johannesjoos Warnings are just warnings. They don’t halt the script operation in PHP. Actual errors would cause problems that could make the site not work properly, but warnings typically are found in code which doesn’t account for all cases properly. PHP can handle them just fine, for the most part.

As of PHP 7, a fair number of “warnings” get graduated to “errors” and those would likely need to be fixed by then, but generally speaking simply not showing the issue is enough. Fixing it is up to you or the developer. For a non-numeric warning, I expect it is because some option in the plugin is not initialized properly, thus resulting in the warning message. But the code will likely just set it to zero anyway, as a default.