If the debugger is attached and an uncaught exception occurs then I get the "paused" message on the device showing the line which errored and don't get the exception details dialog until I step or run the program.
B4X:
Dim ba As Byte
If ba = Null Then 'exception causes pause here with no breakpoint set
...
End If
Is this by design, a bug or an unavoidable consequence of the debugger architecture?
This is by design. You can see the exception in the variables section under LastException. It should appear red. Note that if the exception happens in a service then the next step after this pause is that your program crashes and exits.