UserAgent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/66.0.3359.139 Safari/537.36

Steps to reproduce the problem:
I'm getting consistent crashes when executing a certain line of code in the debugger. It only happens in this specific scenario, so I uploaded the full version of my app. The crash does not happen when the code executes normally (without debugging).

1. Open http://physics.rivsoft.net/Stack
2. Click the "pause" and "restart" buttons in top left.
3. Click step forward button until the cubes in the 3D view are nearly touching (right click to rotate for better view).
4. Open dev tools and navigate to static/js/physics/collision/colHullHull.js
5. Place a breakpoint on line 89 `vec3.copy(this.cacheAxis, sat.normal);`
6. Press step forward button again to hit the breakpoint
7. Press F10 to step to the next line
8. Page crashes

I recorded a video of the process here: https://youtu.be/DAwFrtPo8bs

What is the expected behavior?

What went wrong?
Page always crashes when stepping through a certain line in dev tools

Did this work before? N/A 

Chrome version: 66.0.3359.139  Channel: stable
OS Version: 10.0
Flash Version: