The markers and Tutors are experiencing an error when trying to mark assignments and loading the marking page. It looks like it is timing out before it can load.
After refreshing the page it does load but it's very slow.

In our case we have 2400 students enrolled into the course and assignment page take almost 3 minutes to load.

Debug the mod_assign, there is a function user_get_user_details() been called in externallib.php at line number 2666. which mean we are getting 2400 students detail for single user marking page, which obviously will be very expensive.

Instead if we just get the user IDs that will be a huge improvement in the performance, in our case it was 3 minutes to less then 3 seconds.

When we navigation to next student we already making an ajax call to the student detail. so we don't really need all the student data on marking page .

Current Code:
if (!$assign->is_blind_marking() && !$params['onlyids'])

{ $userdetails = user_get_user_details($record, $course); }

else

{ $userdetails = array('id' => $record->id); }

*Proposed solution: *
$userdetails = array('id' => $record->id);