Create and assignment and turn "students submit in groups"
Leave the grouping for student groups set to None
Try and submit something as a student.

Error:

Can not find data record in database table groups.

More information about this error

Debug info: SELECT * FROM

WHERE id = ?
[array (
0 => '0',
)]
Error code: invalidrecord
Stack trace:
line 1451 of /lib/dml/moodle_database.php: dml_missing_record_exception thrown
line 1427 of /lib/dml/moodle_database.php: call to moodle_database->get_record_select()
line 5432 of /mod/assign/locallib.php: call to moodle_database->get_record()
line 136 of /mod/assign/classes/event/assessable_submitted.php: call to assign->format_submission_for_log()
line 700 of /lib/classes/event/base.php: call to mod_assign\event\assessable_submitted->get_legacy_logdata()
line 5650 of /mod/assign/locallib.php: call to core\event\base->trigger()
line 5685 of /mod/assign/locallib.php: call to assign->save_submission()
line 388 of /mod/assign/locallib.php: call to assign->process_save_submission()
line 53 of /mod/assign/view.php: call to assign->view()