Same problem as http://tracker.moodle.org/browse/MDL-26416, except the error occurs in the "Response" section of the quiz results.

Debug info: BIGINT UNSIGNED value is out of range in '(`xxx`.`qa`.`timefinish` - `xxx`.`qa`.`timestart`)'
SELECT CONCAT(u.id, '#', COALESCE(qa.attempt, 0)) AS concattedid, qa.uniqueid, qa.id AS attempt, u.id AS userid, u.idnumber, u.firstname, u.lastname, u.institution, u.department, u.email, u.picture, u.imagealt, qa.sumgrades, qa.timefinish, qa.timestart, qa.timefinish - qa.timestart AS duration, qa.layout FROM mdl_user u LEFT JOIN mdl_quiz_attempts qa ON qa.userid = u.id AND qa.quiz = ? WHERE qa.id IS NOT NULL AND qa.preview = 0 ORDER BY concattedid ASC LIMIT 0, 30