Summary:
This was originally reported as a random error showing up in some rooms after updating to 2.2.2.

Notice: Undefined offset: 9 in /home/ubuntu/xdev/html/moodle34/mod/bigbluebuttonbn/locallib.php on line 709

Notice: Undefined property: stdClass::$id in /home/ubuntu/xdev/html/moodle34/mod/bigbluebuttonbn/locallib.php on line 907
After further investigation it was discovered that the error is shown when a room that was configured with participation rules including custom roles, and one or some of those roles were removed (or updated).

Steps to reproduce:

• Create a custom role
• Create a new room
• Assign a participation rule to the room where the custom role is moderator
• Save the room
• Delete the custom role
• Display the room

Expected behavior:

Same as for Users, the role should just not be considered if it is missing.

Additional notes:

As a workaround the room can be edited and saved again. That will update the permission list (as the rule is not considered if the role is not found) and fix the reference in the database.