Hi Johnny,
As this is just a notice from PHP for a missing variable, you are able to disable these notices. I will tell you how to disable these notices for now. In the following update, the code you add now, will be automatically removed when we roll out the new version of Buttonizer.
Put inside the /wp-content/plugins/buttonizer/buttonizer.php on top of the file the following code:
ini_set('error_reporting', E_ERROR);
error_reporting(E_ERROR);
This means it wil only show and log the real PHP errors, but won’t show the notices of variables that are missing. So as I am right, it won’t flood your logs anymore.
Let me know if this is a good temporarely solution.
– Jasper