A user informed us that some (not all) of their h5p assets (via Moodle plugin v1.6) have recently stopped working on Chrome. They isolated the issue as being due to the AdBlock plugin blocking iframes with src=”about:blank”.
They’ve updated \mod_h5p\view_assets->outputview () to use ‘#’ instead of ‘about:blank’, which has resolved the issue for now.
Edit: The list of ads EasyList quickly fixed this problem so H5P didn't have to do anything. Also note that '#' is not an allowed src for an iframe.
1. Add src=# or other trick to avoid the problem described in the description of this issue.