some notices in error log

with wordpress 4.4

i can confirm same error on wp 4.4,
visible with WP_DEBUG=true,
it can even spam the notice multiple times in every backoffice post type archive page,
I tried to find the error but could not do anything.

I don’t know if you’re supposed to modify core files, but I had to do it to fix the issue.

The issue is that on line 3611, $object_terms is an empty array which is then iterated and points to an object that doesn’t exist.

To fix it, go to incluses/taxonomy.php and replace lines 3612 and 3613 which should look like this:

foreach ( (array) $terms as $term )
		$object_terms[$term->object_id][$term->taxonomy][] = $term;

with this updated code which checks to see if the array is not empty before iterating through it:

if (sizeof($object_terms) > 0) {
		foreach ($terms as $term){
			$object_terms[$term->object_id][$term->taxonomy][] = $term;
		}
	}

I don’t know if you’re supposed to modify core files, but I had to do it to fix the issue.

You’re not. You’ll lose all of your changes, you may break other things and you will lose your work when WordPress updates.

Perhaps the plugin author will reply with a fix?