Re: Grades not transferring for most students

Here are the last few lines of the trace:

Skipping - Invalid grade for the user '966' in the tool '40' for the course '258'.
Skipping - Invalid grade for the user '972' in the tool '40' for the course '258'.
Completed - Synced grades for tool '40' in the course '258'. Processed 29 users; sent 0 grades.

Starting - Grade sync for shared tool '41' for the course '258'.
Failed - Invalid contextid '5089' for the tool '41'.
Completed - Synced grades for tool '41' in the course '258'. Processed 1 users; sent 0 grades.

Starting - Grade sync for shared tool '42' for the course '258'.
Completed - Synced grades for tool '42' in the course '258'. Processed 0 users; sent 0 grades.


Starting - Grade sync for shared tool '43' for the course '258'.
... used 1155 dbqueries
... used 1.9368200302124 seconds
Scheduled task failed: Publier comme outil LTI de synchro des notes (enrol_lti\task\sync_grades),Erreur de programmation détectée. Ceci doit être corrigé par un programmeur : Invalid context id specified context::instance_by_id()