iOS crash when device sleeps

Update:
It’s possible that the crash happens when a user forcibly quits the game when it’s not responding to input, and the cause of that seems similar to what’s discussed here: Crash when app comes back from sleep - #25 by britzl
There are 2 scripting errors in analytics data. The first is:

argument #1 contains one or more values which are not numbers: vmath.vector3(nan, nan, nan)

which occurs when we’re determining how to scroll the camera in response to touch drag input:

local world_diff = camera.screen_to_world(cameraId, screen) - camera.screen_to_world(cameraId, self.pressed_position)

It seems plausible that this is caused by window width/height being 0, as discussed in the other thread, and we can easily guard against that.

The other one is similar - we forward input to a cursor object from a controller (based on defold-input/controller.script) but again we convert from screen to world space before doing so.

What doesn’t make sense is why the game is receiving input at the moment it’s resuming from sleep.