When trying to Get the Grader option in Single simple discussion Forums type ** from "Activities block" in course, and invalidrecordunknow is showed.

Steps to replicate:

1- Go or create any Moodle course.

2- Create a new forum.

3- Enable "whole forum grading" with point or scale.

4- Select the type: "single simple discussion"

5- Save a return to course.

6- Go or enable the "Activities" Block on course.

7- Once in "Activities" Block, select the "forums" option.

8- Click on the forum you created on step 2 to 5.

9- Click on "Grade users" buttom.

10- The error is displayed.

Troubleshooting:

You can join the grader for this kind of forum from gradebook and normal menu course interface.

{{}}

Debugging mode displaying message:

Archivo: /lib/dml/moodle_database.php
Línea: 1674
Rastreo de pila:

SELECT c.*
{{ FROM {course_modules} cm}}
{{ JOIN {course} c ON c.id = cm.course}}
{{ WHERE cm.id = ?}}
[array (
{{ 0 => 0,}}
)]
Error code: invalidrecordunknown
* line 1674 of /lib/dml/moodle_database.php: dml_missing_record_exception thrown
* line 2306 of /lib/modinfolib.php: call to moodle_database->get_record_sql()
* line 4129 of /course/externallib.php: call to get_course_and_cm_from_cmid()
* line 261 of /lib/externallib.php: call to core_course_external::get_enrolled_users_by_cmid()
* line 81 of /lib/ajax/service.php: call to external_api::call_external_function()