I have a plugin for a site that creates multiple custom post types (CPT). Each with their own custom capability specified via the capability_type attribute of the register_post_type() function. I copy-and-pasted the code block for each register_post_type() from the first one, which includes the capability_type as an array, ie. array('type' , 'types'). Some of the subsequent CPT didn’t need multiple capability types so I was receiving the warning ‘Notice: Undefined offset: 1 in post.php’ due to a single item in the array. The fix was to remove the array wrapping the single value, et voila, no more warning.

Published on January 17, 2024