Unity/WebGL and asm.js related crash in MS Edge

Question

I have a very basic Unity app that's essentially a test harness for a proprietary framework. It runs fine in Chrome, Firefox and Safari. Edge is a different story.

In Edge 12, with asm.js disabled, it takes a very long time to load - roughly 90 seconds, compared with 15-20 in other browsers.

In Edge 12 or 13 with asm.js enabled, it loads quickly, but crashes the tab immediately when the the Unity app starts up. I've been able to figure out that the "preRun" callback gets called, but the "postRun" callback does not.

I can't figure out how to start debugging this - Edge disables asm.js if the Dev Tools debugger is open, and detaching the debugger also disables the JS console. I'm unable to attach the Unity debugger because the crash seems to happen before I get to that point.

Is there some kind of log from Edge where I could find anything about the crash, maybe even a JS stack trace?

Answer 1

This is due to a bug in Edge in our asm.js specialization code (which I am the owner of). Thanks for reporting the issue, I'll try to get a patch out to fix this soon! If anyone else is hitting a crash in asm.js, feel free to send me a message and I'll happily work with you to get a fix (and find a workaround in the meantime).