Assignment 421 and 497 are each other’s parents, which the Assignment.observers() function doesn’t like, because it recursively invokes parent.observers().

Causes failing page load of http://department.st.ewi.tudelft.nl/weblab/edition/in4303-2012-2013

Submitted by Elmer van Chastelet on 13 November 2013 at 17:12

To be precise, the following 3 AssignmentCollections have a .parent that is also in their .assignments:
446
421
445

(scanned the complete set of assignments)

Added validation on AssignmentCollection to check for cycle.
I haven’t found any suspicious code which could cause this. Maybe it is already fixed in the past, as there are validation statements in the .up(),.down(),.toParent(),.toNextSibling() methods that validate that the parent is set correctly.

Seems to be already fixed previously