Built project crashing in 5.6.4p4, dmp & log included

I've been getting reports of crashes in my Unity 5.6.4p4 (latest 5.x available) builds from playtesters. Checking the output log brings this:

I've read elsewhere that this means Unity doesn't know enough about the crash location. So, here is the whole crash report -- I'm hoping someone from the Unity development team can look into this!

EDIT: It appears to happen on program exit.

- Phr00t