Deleting objects at editor time.

The "foreach" loop has some special restraints on it that a normal "for" loop doesn't. For example, if you are modifying a collection while iterating over it then it will break. I don't know that it will fix your problem, but I would have tried something like this:


for (int i = obstaclesParent.childcount - 1; i >= 0; --i)
{
DestroyImmediate(obstaclesParent.GetChild(i).gameObject);
}


*Note that I didn't try compiling this code and am typing it from memory so its entirely possible that I got something a little off - hopefully it just gives you the correct general idea.

Also, I think "DestroyImmediate" is synchronous and that it doesn't wait a frame to act on the game object like "Destroy" does. It should be able to happen in one frame regardless of how long it takes.