Moodle in English: Error when trying to view enrolled users

Error when trying to view enrolled users

by Dave Pacione - Tuesday, September 10, 2013, 9:00 PM

Hi All,

Moodle 2.5 2.5.1+ (Build: 20130808)Version 2013051401.08on Windows server 2008r2, iis7.5, ms sql server 2008r2

I'm getting the error:

Coding error detected, it must be fixed by a programmer: Invalid context id specified context::instance_by_id()

when clicking course administration>users>enrolled users | enrolment methods.

With debugging on I see:

Debug info: Error code: codingerror

Stack trace:

line 5178 of \lib\accesslib.php: coding_exception thrown

line 49 of \enrol\cohort\lib.php: call to context::instance_by_id()

line 506 of \enrol\locallib.php: call to enrol_cohort_plugin->get_instance_name()

line 152 of \enrol\users_forms.php: call to course_enrolment_manager->get_enrolment_instance_names()

line 191 of \lib\formslib.php: call to enrol_users_filter_form->definition()

line 205 of \enrol\users.php: call to moodleform->moodleform()

Output buffer: Notice: Trying to get property of non-object in D:\inetpub\moodle_dev\enrol\cohort\lib.php on line 49 Notice: Trying to get property of non-object in D:\inetpub\moodle_dev\enrol\cohort\lib.php on line 49

line 49 of enrol\cohort\lib.php is:

$cohortname = format_string($cohort->name, true, array('context'=>context::instance_by_id($cohort->contextid)));

This only occurs for a few courses but I can't see what's different about them compared to the courses that don't have a problem

Any ideas would be very much appreciated

Re: Error when trying to view enrolled users

by Emma Richardson - Tuesday, September 10, 2013, 10:25 PM

Do you have different enrolment methods activated for the specified courses? Perhaps a cohort enrolment where the cohort has been deleted from the database somehow?

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Re: Error when trying to view enrolled users

by Dave Pacione - Tuesday, September 10, 2013, 10:40 PM

Hi Emma thanks for your reply. We enrol all students via cohorts and teachers using manual enrolment on an ad hoc basis. The students are all enrolled as expected and as a workaround I'm using the upload users via csv to enrol teachers onto the troublesome courses.

Unfortunately I can't access the enrolment methods page either (same error) so can't check which cohorts have been added to the courses. I'm trying to chase up that info from our eLearning team who initially set the courses up.

I can check enrolled users and their roles by viewing the participants link for the courses so the database is being populated.

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Re: Error when trying to view enrolled users

by Emma Richardson - Wednesday, September 11, 2013, 1:35 AM

You might check the database for cohort id in relation to users enrolled in the class. Then check that the cohort still exists. It also might be that in some classes they enrolled the students and in the ones that aren't working, they enrolled the cohort. Perhaps something is messed up with cohorts in your install, in which case a reinstall or upgrade might be the only solution.

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Re: Error when trying to view enrolled users

by Dave Pacione - Wednesday, September 11, 2013, 6:39 PM

Hi Emma, the cohorts with students synced to the course are all present and correct and there are no students with userids and cohortids in the cohort_members table referring to a non-existent cohort.

Might be I need to try and upgrade to 2.5.2 as you suggested and see what happens.

The idea that there's an orphan record somewhere does sound like the right track to investigate as a similar post describing the same error for repositories with an orphan record being the root of the issue.

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Re: Error when trying to view enrolled users

by Emma Richardson - Wednesday, September 11, 2013, 7:56 PM

Sorry to not be of more help - of course, if it is an orphan record, an upgrade might not help. Have you tried a repair on the database?

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Re: Error when trying to view enrolled users

by Dave Pacione - Thursday, January 9, 2014, 7:31 PM

Hi Emma, it was indeed a missing cohort, - as you suggested - that was being referred to in mdl_enrol table (customint1 column). Removing the record in mdl_enrol that referred to the non-existent cohort did the trick. Simple really.

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Re: Error when trying to view enrolled users

by Emma Richardson - Thursday, January 9, 2014, 10:48 PM

Good deal. I thought it must be something like that but it is always hard to really figure out when you are not actually in someone's site or database!

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Re: Error when trying to view enrolled users

by Marko Simić - Monday, December 2, 2013, 7:15 AM

I am getting the same message. The only thing that was changed in past few hours is that one cohort, that was experimental a while ago with some users who are now in other cohorts also, has been deleted. This appears only in new courses; however, before that experimental cohort was deleted users whitin it appeared to be enroled in new courses...

Now I have a number of new courses waiting for the users to be enrolled but when I go to administration>users>enrolled users (or enrolment methods) I get this message.

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Re: Error when trying to view enrolled users

by Marko Simić - Monday, December 2, 2013, 8:08 AM

I resolved the problem, at least temporarly. I inserted the cohort directly through db with corresponding id (it was 1 because it was the first cohort created) and now it works.

But I will still have to remove that first cohort...

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Re: Error when trying to view enrolled users

by Dave Pacione - Wednesday, January 8, 2014, 5:24 PM

Hi Marko, if you're still interested I resolved the issue just this week. In our case it was due to an entry in mdl_enrol that didn't correspond to a cohort in mdl_cohort.

Mdl_enrol contains a column called customint1 which contains the cohort id for each cohort that is synced to enrol onto a course.

select id, courseid, customint1 from mdl_enrol where coursed = <the problem course id>

I used the list of customint values returned from the above query from our problem course to check for records in mdl_cohort and found that one customint value in mdl_enrol didn't exist in mdl_cohort.

Deleting this orphan record in mdl_enrol did the trick.

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Error when trying to view enrolled users