Database insert error when adding a MULTICHOICE question using this format:* San Francisco:

Debug info: Incorrect integer value: 'C' for column 'answerformat' at row 1
UPDATE mdl_question_answers SET question = ?,answer = ?,feedback = ?,answerformat = ?,fraction = ?,feedbackformat = ? WHERE id=?
[array (
0 => 73,
1 => 'C',
2 => 'OK',
3 => 'C',
4 => '1',
5 => '1',
6 => 113,
)]
Stack trace:

line 397 of /lib/dml/moodle_database.php: dml_write_exception thrown
line 984 of /lib/dml/mysqli_native_moodle_database.php: call to moodle_database->query_end()
line 1016 of /lib/dml/mysqli_native_moodle_database.php: call to mysqli_native_moodle_database->update_record_raw()
line 92 of /question/type/multichoice/questiontype.php: call to mysqli_native_moodle_database->update_record()
line 424 of /question/type/questiontypebase.php: call to qtype_multichoice->save_question_options()
line 139 of /question/type/multianswer/questiontype.php: call to question_type->save_question()
line 424 of /question/type/questiontypebase.php: call to qtype_multianswer->save_question_options()
line 181 of /question/type/multianswer/questiontype.php: call to question_type->save_question()
line 264 of /question/question.php: call to qtype_multianswer->save_question()