Bug? Null pointer exceptions after sleep in resumable sub

First spotted in B4A 12.50, still happening in 12.80.
I've tested this on a few devices with different Android versions and it crashes on all three.

If I call MsgboxAsync or Msgbox2Async after a sleep within a ResumableSub in a class module, the app crashes.
If I have a try...catch block after a sleep within a ResumableSub in a class module, the app crashes.

This can be reproduced in the attached project. Normal tap on the button to reproduce case 1, long tap to reproduce case 2.

In both cases, if there is a breakpoint within the sub, the app does no crash regardless of whether the breakpoint is hit.

Related thread with a bit more explanation here :

One of the reasons that this could be a true bug in B4A is that they try/catch example sub works as expected under B4J. B4J example can be found here: https://www.b4x.com/android/forum/threads/errors-after-going-async.159562/post-979776

This is indeed a bug.

FWIW, it doesn't happen in B4XPages. B4XPages simplifies the overly complicated activities life cycle. I recommend all new projects to be based on B4XPages.

Erel said:

This is indeed a bug.

FWIW, it doesn't happen in B4XPages. B4XPages simplifies the overly complicated activities life cycle. I recommend all new projects to be based on B4XPages.

Click to expand...

I've only just got round to "going async" on my main android product, so I don't know when I will get around to converting it to B4XPages.
Thanks for confirmation.