Update course blocks fails to take effect

[mikedawson]

Creating an new course and assigning students, classes, and blocks seems to work fine. However modifying an existing course ( e.g. 2252 ) to add a new block to the course list (e.g. TDP English ID 2865) after clicking submit it does not appear to take effect and when opening the course again the block that was added to the course is no longer in the selected list.