OJS 3.1.1-2 unable to edit review details

When you click to edit a reviewer’s review due date, you can change the information in the edit window, but clicking “OK” it just hangs at a spinning circle indefinitely. Error log shows:

[Tue Aug 28 10:31:01.089983 2018] [:error] [pid 29781:tid 139658931443456] [client xxx.xxx.xxx.xxx:50827] PHP Notice: Undefined property: ReviewAssignment::$getDateDue in /var/www/html/lib/pkp/controllers/grid/users/reviewer/form/EditReviewForm.inc.php on line 135, referer: referrerURL
[Tue Aug 28 10:31:01.090175 2018] [:error] [pid 29781:tid 139658931443456] [client xxx.xxx.xxx.xxx:50827] ojs2: Unrecognized DAO StageAssignmentDao!, referer: referrerURL

Could this be the same as:

Thanks!

I made the following two changes manually to resolve this for now as we are trying to go live on 3.1.1-2 and had to be able to do this:

It seemed to work.