Java error wpProQuiz

This recently started occurring. I have it on both Safari and Firefox. I believe this is in the wpProQuiz_front.js

Any help would be great. While I have gotten this far, I am not a coder by any means.

I have Enable SCRIPT_DEBUG, which didn’t fix it and then I went onto both Safari and firefox and did a diagnosis. They both came back with:

TypeError: null is not an object (evaluating ‘json.lock’) wpProQuiz_front.js:1953

Below are the lines before 1953 and after:

(1948) plugin.methode.ajax({
action: ‘wp_pro_quiz_check_lock’,
quizId: config.quizId
}, function(json) {

(1953) if(json.lock != undefined) {
quizStatus.isLocked = json.lock.is;

if(json.lock.pre) {
$e.find(‘input[name=”restartQuiz”]’).hide();
(1958) }