H5P embedded in lessons is creating session mutation error

Submitted by DP-OLS on Thu, 09/04/2025 - 08:17
Forums: 
General discussion

Hi, 

We've just upgraded to Moodle 4.5 and in reviewing our lessons I am seeing an error come up with embedded H5P. The error is as follows: 

Script /mod/hvp/embed.php?id=1722 mutated the session after it was closed: $SESSION->cachestore_session: default_session-core/navigation_cache,default_session-core/coursecat,default_session-core/navigation_expandcourse,default_session-core/courseeditorstate,default_session-core/grade_categories

  • line 807 of /lib/classes/session/manager.php: call to debugging()
  • line 167 of /lib/classes/shutdown_manager.php: call to core\session\manager::check_mutated_closed_session()
  • line ? of unknownfile: call to core_shutdown_manager::shutdown_handler()

This error seems to appear with every type of H5P content if embedded. It does not occur if not embedded or if embedded via the content bank rather than an iframe. However, we use iframes and want to remove this error. We cannot tell what effect it is having - the H5P content can still be completed. 

Our H5P plugin is version 

1.27.22024120900 Our Moodle version is Moodle 4.5.6+ (Build: 20250819) Does anyone have any idea what is happening here?  Thank you for considering this issue.