I have a discussion forum where students post every week. The first is "Forum for standard use" and the second one is "Q&A forum" but the problem happens on both of them.
When I click to grade, the first person it prompts me to grade is me (the teacher). When I click to move to the next student, or when I select a student from a list of students, it gives me this error.
It never does load the student which means I cannot easily grade my students, which is clearly a problem.
I turned on full debugging to see what messages I can see and I received the following:
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invalidresponse
Invalid response value detected
File: /lib/externallib.php
Line: 459
discussions => Invalid response value detected: posts => Invalid response value detected: userposts => Invalid response value detected: timecreated => Invalid response value detected: Invalid external api response: the value is "" of PHP type "NULL", the server was expecting "int" type
Error code: invalidresponse
* line 459 of /lib/externallib.php: invalid_response_exception thrown
* line 267 of /lib/externallib.php: call to external_api::clean_returnvalue()
* line 81 of /lib/ajax/service.php: call to external_api::call_external_function()
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I do have a few plugins but I don't think any of them are connected to the forum grading process.
Any ideas how I can fix this problem?