[Plugin: Advanced Custom Fields] htmlspecialchars() expects parameter 1 to be string

I am getting the same message. Any fix for this?

I just got this error and figured it out. Go to settings->advanced custom fields and edit the field group that’s causing the error. In my case, in my field group I had accidentally clicked the “add field” button and left it there mostly empty (no name, etc.) Deleting that field resolved the issue.

Thank you so much! That’s exactly what I needed. Hadn’t even realized I’d added an empty field.

thanks. I switched to using something else as I couldn’t wait for a fix.
But this will be useful for the plugin author.