Instead of the mark and mark code boxes, there is a grey padlock preventing me from returning a mark.
I want to return marks. When I go in to the class screen, some or all of the class have their mark and mark code boxes replaced with a grey padlock.
The reason is that there has been at least one board for this class which has passed, with no future board dates set.
When the new board is arranged you will be able to return marks again.
If you want to return resit marks, remember to create a new marks return so the first attempt marks are not overwritten.