Error message:

You should really redirect before you start page output
line 789 of /lib/outputrenderers.php: call to debugging()
line 2649 of /lib/weblib.php: call to core_renderer->redirect_message()
line 161 of /mod/scheduler/teacherview.php: call to redirect()
line 87 of /mod/scheduler/view.php: call to include()

Therefore, Automatic redirect failed.