1. On the Moodle Front Page click Courses under Site Administration. The Courses sub-menu is displayed.
2. Click Add/Edit Courses.
3. Moodle displays the Course Categories screen: /course/index.php?categoryedit=on

If you click the DELETE icon in the Edit column of any of the Course Categories that are displayed on the table Moodle throws a "Error reading from database" error:

Debug info: SQLState: 42000<br>
Error Code: 8156<br>
Message: [Microsoft][SQL Server Native Client 10.0][SQL Server]The column 'id' was specified multiple times for 'q'.<br>
SQLState: 42000<br>
Error Code: 8156<br>
Message: [Microsoft][SQL Server Native Client 10.0][SQL Server]The column 'id' was specified multiple times for 'q'.<br>

SELECT q.* FROM (SELECT TOP 9223372036854775806 ROW_NUMBER() OVER(ORDER BY id) AS sqlsrvrownumber, q.* FROM (SELECT *
FROM mdl_question q
JOIN mdl_question_categories qc ON qc.id = q.category
WHERE qc.contextid = '27202' AND q.parent = 0) AS q) AS q WHERE q.sqlsrvrownumber > 0 AND q.sqlsrvrownumber <= 1
[array (
0 => '27202',
)]
Stack trace:

• line 391 of \lib\dml\moodle_database.php: dml_read_exception thrown
• line 252 of \lib\dml\sqlsrv_native_moodle_database.php: call to moodle_database->query_end()
• line 363 of \lib\dml\sqlsrv_native_moodle_database.php: call to sqlsrv_native_moodle_database->query_end()
• line 761 of \lib\dml\sqlsrv_native_moodle_database.php: call to sqlsrv_native_moodle_database->do_query()
• line 1553 of \lib\dml\moodle_database.php: call to sqlsrv_native_moodle_database->get_recordset_sql()
• line 396 of \lib\questionlib.php: call to moodle_database->record_exists_sql()
• line 55 of \course\delete_category_form.php: call to question_context_has_any_questions()
• line 152 of \lib\formslib.php: call to delete_category_form->definition()
• line 130 of \course\index.php: call to moodleform->moodleform()

If you click the Continue button below this error you are redirected to the Moodle Front Page.