When a script with a property that is a url is added to a game object that has other game objects as children (and is a part of a collection), marking that script in the editor hangs it.
Steps to reproduce:
Create a collection
Add a game object
Add another game object and set it as a child to the first one
I had a a similar problem but instead of editor freezing the properties window breaks and shows nothing of use.
“solved” it by putting the scripts containing the msg.url() properties in the child go. This seems like a fairly major bug.
Ah, yes, this bug is a bit nasty. We need to fix it. For some reason I’m unable to access our bug tracker at the moment so I can’t see if we already have a ticket for this or not.