I thought I had found a simpler repro sequence but it actually doesn't really always happen right away, here it is anyway:

erase all settings on both computers

start mojo from debugger (start new instance) on main pc; accept license
start mojo on 2nd computer; accept license

go to mouseover settings and connect the 2 screen (I used my main on the right of the 2nd pc; if that matters)

using mouseover start wow on 2nd pc

start wow on first pc

type stuff on bot password boxes

setup pause has windowbroadcast toggle; use it on/off a few times

toggle wow from windowed to fullscreen and back

type some more

crash