Plugin doesn't work with debugging and Opencast maintenance message

[t-schroeder]

Requests to local/och5pcore/ajax.php fail under these conditions:

1. Debugging is enabled and set to DEVELOPER level.
2. A maintenance message has been configured in tool_opencast settings.

They result in this exception:

Coding error detected, it must be fixed by a programmer: $PAGE->context was not set. You may have forgotten to call require_login() or $PAGE->set_context()

Steps to reproduce

• block_opencast v4.5-r4
• tool_opencast v4.5-r4
• Site administration -> Development -> Debugging
  • debug: DEVELOPER
  • debugdisplay: Yes
• Site administration -> Plugins -> Admin tools -> Opencast API -> Configuration
  • maintenancemode_1: Enabled
  • maintenancemode_message_1: test
• Go to a course -> Content bank
  • Add -> Interactive Video
  • Click the button with the "+" symbol for adding a video file.
  • There is no option to select an Opencast video in the modal that opens up.

Note: Disabling the Opencast maintenance mode again doesn't help. Disabling Debugging does help.