After Upgrade to Moodle 5 all Coderunner questions stop working: missing prototype

[tbutsch]

We upgraded to Moodle 5. Without any errors. And we upgraded to newest qtype-coderunner. No errors.

Now all the questions do not work anymore. Please see the attached screenshots.

[trampgeek]

Prior to Moodle5.0, all the built-in prototypes were in a question category CR_PROTOTYPES at the system level. In Moodle 5.0 there is no such category. So instead, the prototypes are stored in a System Shared Question Bank belonging to the front page course. This should have been created and populated during the install.

To check what's happened, you need to be a Moodle administrator. Login to the site and click the Home link at the top (in the list Moodle5.0, Home, Dashboard, My courses, ...). That puts you in the Front Page context, and you should see a list of links Home, Settings, Participants, Reports, Question banks, More. Click the Question banks link.

You should see a System shared question bank in that context. Do you?

If so, click the link to it. What questions do you find? You should have a set with names beginning BUILTIN_PROTOTYPE. Do you?

[tbutsch]

I found them. But I have three of them. Please see attached screenshots.

[trampgeek]

Certainly there should be only one such question bank containing exactly one copy of those prototypes. Multiple copies will break CodeRunner.

I see the first question bank is dated 29 January, well before the main release of Moodle 5.0 and before the required CodeRunner updates. Is that a wrong date, or were you using pre-release/development versions of the code?

I don't know how the multiple copies of the question bank have happened - the code should check for the existence of that question bank before creating it. Please let me know if you have any recollections of odd things happening or other suggestions.

For now, though, I suggest you delete all the BUILT_IN_PROTOTYPE CodeRunner questions from the first two sets (dated 29 January and 23 May). You can probably also delete the question banks themselves unless there are other questions besides CodeRunner prototypes in them. Let me know if that solves the immediate problem.

[faisalm-pk]

I am facing the same issue as the owner of this post.

I can see the BUILT_IN_PROTOTYPE and can create and use the CodeRunner questions in that front page course. But the same error as mentioned above is shown in all of the other courses, and I also can not find any question type in the drop-down. It is working fine on the backup site (Moodle v4.5.3+ and CodeRunner v5.7.1+) but facing the above issues in Upgraded site (Moodle v5.0.1 and CodeRunner v5.7.1+).

I have updated the CodeRunner Plugin to v5.7.1+ before Moodle upgrade from 4.5.3 to 5.0.1, I was not able to reinstall the plugin as it is already the latest version. I did the following.

1. Deleted the front course question banks.
2. Renamed the only remaining system question bank to something xyz (I think at-least 1 question bank is mandatory).
3. Edited the CodeRunner plugin version file and incremented the last digit of version by 1.
4. Reinstalled (kind of update by incrementing the version by 1) and it installed successfully.
5. It created the "System shared question bank", I deleted the previous xyz Question Bank.

Still the same issue as mentioned above.... Kindly let me know if I am missing something?

It also creates a new "System shared question bank" whenever I update the plugin by incrementing the version by 1. Also in the previous installation there was a category "SQL Prototype and samples (Experimental)" which was also available in "System shared question bank" when I upgraded the Moodle but I can not see it after the above steps but CR_PROTOTYPES.

For now I am reverting to Moodle 4.5.3 as we have exams this week. Hope you will find time to look into this soon. Thanks for your time and efforts.

[trampgeek]

Thanks for reporting. Reverting to Moodle 4.5 for the exam was certainly the right call. Upgrading just before exams was a trifle ... brave?! Did you notice in the release notes for the latest version of CodeRunner I describe Moodle 5.0 support as alpha-level? It runs all the tests on my system and I can't replicate the problems you're having, but there are complexities with shared question banks that haven't been tested in a production environment.

It's difficult to debug your problems since I can't replicate them. Certainly on my Moodle 5.0 system, if I bump the version number I do not get a new system shared question bank.

Can you confirm, please that:

(a) The new system shared question banks you were getting were in the front course, not in "normal" courses?
(b) That the newly created (extra) system shared question banks each had a question category CR_PROTOTYPES and that all the usual CodeRunner BUILT_IN_PROTOTYPE_xxxx questions were present in it?

It's odd that you're getting multiple instances of the system shared question bank in the front course, because that question bank is created by a Moodle core function that I call during updates: "get_default_open_instance_system_type()". It's defined to return the system type qbank instance for a given course (the 'front' course in this case) with an option to create it if it doesn't exist. As a comment in the function itself says "We should only ever have 1 of these". This is not my code!

Certainly the duplication of those questions will break CodeRunner. But I would like someone to confirm, please, that eliminating that duplication by deleting all but one of the sets of prototypes, at least gets CodeRunner going again?

[lucaboesch]

This would be fixed by https://tracker.moodle.org/browse/MDL-84695.
The necessary code is there.
Only thing: on MSSQL, which I cannot test, an automated test seems not running.

In my installation, I hotfixed by taking the code there.

[trampgeek]

Many thanks Luca. I hadn't made the connection to your earlier postings on the CodeRunner developer forum. Pending a fix of the bug in Moodle core I'll see if I can come up with a workaround in CodeRunner. In-Confidence

…

________________________________ From: Luca Bösch ***@***.***> Sent: Thursday, 12 June 2025 6:21 pm To: trampgeek/moodle-qtype_coderunner ***@***.***> Cc: Richard Lobb ***@***.***>; Comment ***@***.***> Subject: Re: [trampgeek/moodle-qtype_coderunner] After Upgrade to Moodle 5 all Coderunner questions stop working: missing prototype (Issue #255) [https://avatars.githubusercontent.com/u/377279?s=20&v=4]lucaboesch left a comment (trampgeek/moodle-qtype_coderunner#255)<#255 (comment)> This would be fixed by https://tracker.moodle.org/browse/MDL-84695. The necessary code is there. Only thing: on MSSQL, which I cannot test, an automated test seems not running. In my installation, I hotfixed by taking the code there. — Reply to this email directly, view it on GitHub<#255 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/AAIM2VTSVXCWDRG4F5T77AT3DEL47AVCNFSM6AAAAAB6LCOAKGVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDSNRVGI3DENRWGY>. You are receiving this because you commented.Message ID: ***@***.***> This email may be confidential and subject to legal privilege, it may not reflect the views of the University of Canterbury, and it is not guaranteed to be virus free. If you are not an intended recipient, please notify the sender immediately and erase all copies of the message and any attachments.

[helmo-nico]

Hello ! We are experiencing the same issue after upgrading from Moodle 4.4 to Moodle 5.0.1 (Build: 20250629).

We did not encounter this problem on our test instance, but we do see it on our production instances.

When exporting and importing a course from one of our production instances into our test instance, the issue also occurs on the course within the test environment.

I tried deleting and recreating the question bank from the course homepage by importing the prototypes from our test instance, but this did not resolve the issue.

I reviewed the bug report here: https://moodle.atlassian.net/browse/MDL-84695, but I don’t have the technical knowledge to fully understand how it relates to our issue — and more importantly, I couldn’t clearly find when the patch will be released.

Do you know if a fix will also be made available at the plugin level?

[trampgeek]

I would like to see if a work-around was possible in the plugin, but we don't run Moodle 5 here and right now my priority is getting everything ready for my programming course that starts in a week's time.

In an earlier posting, I suggested that the problem would likely be solved simply by finding all the extra copies of the built-in prototypes and deleting them, leaving just one one copy. I didn't get any response confirming or denying the success of that approach. Is that something you'd be able to try and report back on?

[helmo-nico]

Thank you for the suggestion. I checked this using a database query:

SELECT * FROM mdl_question
WHERE name = 'BUILT_IN_PROTOTYPE_c_function'

The query returned only one result.

I also checked that there is only one question category named CR_PROTOTYPES:

SELECT t.*
FROM moodle.mdl_question_categories t
WHERE name = 'CR_PROTOTYPES'

This returned only one result.

The question bank on my homepage does include this CR_PROTOTYPES category containing 19 CodeRunner-type questions.

Do you see what I might have missed?

I have a question that might sound silly, but why not choose to store the question templates in the database?

Anyway, your plugin is widely used and greatly appreciated by our teachers. We are considering launching a sponsorship program to support the development of open-source software. Would receiving such support help sustain the development of your plugin in the long term?

[lucaboesch]

The Moodle Tracker issue https://moodle.atlassian.net/browse/MDL-84695 is now passing green for all database types. Some MSSQL specifics did impede it from passing there.
It will surely be passed along soon and should make Moodle 5.0.2.
There is no possibility fixing this only from the plugin side. Unless fixed, get_qbank_ids_of_type_in_course always returns an insufficient and false result and CodeRunner continues failing.
In https://moodle.atlassian.net/browse/MDL-84695?focusedCommentId=985986 I explained to @helmo-nico and the other readers that it is necessary to edit the query in question/classes/local/bank/question_bank_helper.php.

[ndunand]

A bit late to the game, but...

I had the same problem as OP (playing too much with pre-release versions I guess), but cleaning up extra global qbanks did not do the trick. Also, somehow I always had a new empty global qbank recreated as soon as I deleted the extra ones.

In any case the code fix from @lucaboesch in MDL-84695 fixed the issue.

[trampgeek]

@lucaboesch: Many thanks for jumping in there Luca. I hadn't understood the side effects of the bug. I thought it was just leading to multiple copies of the prototypes as reported by @tbutsch. But it sounds like it's hiding the front-page bank so the prototypes aren't being found at all.

@helmo-nico: Luca's fix sounds like the way to go here. Although I'd be curious to know for the benefit of other teachers who may not have access to the source code whether your problems can be at least temporarily resolved by copying the prototypes you want from the front page shared question bank to your course's shared question bank. But if you do that, you'll need to delete them again when the DB query is fixed.

@ndunand: thanks for confirming the fix.

@helmo-nico: thanks for raising the question of a sponsorship program. I've done most of the development myself over the years, though there have been several other valuable contributors, including Paul McKeown in our department; Tim Hunt at Open University; Luca Bösch in this thread; and two software engineering interns in our department, James Napier and Michelle Hsieh. I'm not the least bit entrepreneurial myself, so I'd love to receive suggestions as how to the maintenance and development might be continued into the future, perhaps inviting existing contributors to be involved?

Regarding your question: "why not choose to store the question templates in the database?" In my very first implementations I had the templates in the database, but I wanted to give teachers the ability to edit these or create their own. Allowing some questions to be prototypes is a way of allowing teachers to edit question types using the existing question-editing infrastructure. The ability to create your own question types is immensely valuable. Essentially all our questions at the University of Canterbury use custom prototypes. And question types like Parsons' Problems and State Sequence Tables (see coderunner.org.nz) would be impossible without that functionality.

[helmo-nico]

@trampgeek Thank you for the explanations; I now better understand the purpose of having the questions in a regular question bank.

If you make progress in your discussions around sponsoring, please don’t hesitate to let me know. I noticed during our upgrade to Moodle 5.0.1 that not all third-party plugin developers had the time needed to update their plugins. I believe this issue is becoming more pronounced due to the accelerated development pace of Moodle, and we think this is a good time to support the development of third-party plugins that make our Moodle so practical to use.

Regarding @lucaboesch's patch, we applied it to our production Moodle instances, and it seems to have resolved the issue on most of them. However, on the Moodle instance from which the screenshots in my previous post were taken, the problem persists. The question types located in the front page question bank do not appear in the list of available question types when editing/creating a CodeRunner question, and existing CodeRunner questions display an error message stating that the prototype used could not be found.

I applied the solution you suggested: I imported the questions directly into the course’s question bank. I can confirm this fixed the issue for that course only.

Interestingly, I didn’t need to delete the existing prototypes from the front page question bank, which leads me to believe that those questions are not being detected by the plugin, despite the patch applied to question_bank_helper.php.

I made this short video to show you:

• Luca’s patch is correctly applied.
• I start by showing the front page question bank, where the prototypes appear to be recognized properly.-
• Then I go to my test course, whose question bank is empty, and try to create a new CodeRunner question — the list of prototypes is empty.

I even ran a new test by cleaning the database of all prototypes directly with a query :

DELETE FROM mdl_question  
WHERE (name LIKE 'BUILT_IN_PROTOTYPE%' OR name LIKE 'BUILTIN_PROTOTYPE%')  
AND qtype = 'coderunner'

Then, I re-imported the prototypes into the front page question bank from one of our Moodle instances where the issue does not occur. I double-checked that Luca’s patch is properly applied. Despite this, the problem persists.

Do you have any other tests you’d like me to try on our stubborn Moodle instance?

[trampgeek]

It does seem like exactly the same bug as before but if you've already patched the query I'm a bit baffled. Have you purged the caches since patching the SQL query?

As a cross check, if you add a multichoice question to the Front Page question bank, can you then use that question in a quiz within a course? You should be able to.