Error reporting and async stack traces have landed in master. This fixes the brutal "undefined var" error that crashes the page without saying which var is undefined. All crashes / "white page" issues should now come with a Photon virtual stack trace that reconstructs client/server control flow transfer that matches the userland program forms. This is a first pass, we're still actively working on it. If you have any issue at all that Photon is either reporting an unhelpful error, not reporting any error at all, etc – please screenshot and post here