?PHP Notice: A non well formed numeric value encountered…

First of all, thanks for this great plugin. When checking my debug.log i noticed a notice coming from this plugin:

?PHP Notice: A non well formed numeric value encountered in path/to/my/website/public_html/wp-content/plugins/remove-orphan-shortcodes/remove-orphan-shortcodes.php on line 32?

Another user mentioned this in another support thread some months ago as well but it seems he never got a reply.

I’m not sure how serious the notice is as the plugin seems to do the job but the error just clogs my logs.