Invalid response value detected: submissiongroup on mod_assign_get_submission_status

Create a course without groups with a student. Create an assignment with the following parameters: Students submit in groups: YES Require group to make submission: NO As admin, enable "Mobile services": Plugins ► Web Services ► Mobile Create a Token for the student user. Click on Site administration ► Plugins ► Web services ► Manage tokens Next, you can do a CURL REST call simulating a WS client with the student user. You need to replace the wstoken, assignid (id of the created assign), userid (student id) and the URL of your moodle instance. curl 'http://localhost/m/stable_master/webservice/rest/server.php?moodlewsrestformat=json' --data 'wsfunction=mod_assign_get_submission_status&assignid=13&userid=6&wstoken=e0962985ad3573791917106a932952f' --compressed Confirm the error is not there anymore.