Additional names debug message in the grade book with ajax enabled.

Error message:
<div class="notifytiny debuggingmessage" data-rel="debugging">You need to update your sql to include additional name fields in the user object.<ul style="text-align: left" data-rel="backtrace"><li>line 3581 of /lib/moodlelib.php: call to debugging()</li><li>line 96 of /grade/report/grader/ajax_callbacks.php: call to fullname()</li></ul></div>

{"message":"The grade entered for Assignment 1 for Test course user 1 is more than the maximum allowed","result":"error"}

Replication steps:

1. Grade Report - turn AJAX editing on in the preferences.
2. Click a cell.
3. Enter a number > 100.
4. Watch the network tab in the dev tools.