As you'd expect …. the hard way …. and repeated it today testing the example on a tablet where I had trouble with the three fingered salute.
Had to switch off and on again!
@dgreen
I took the items from one of my commercial apps where its been in use for over 10 years.
I've also tested this example in A2010 32-bit and A365 64-bit.
Both versions compile and work successfully for me.
Did my app work for you? If not, I suggest you download a fresh copy and save it to a trusted folder.
Otherwise the issue is a problem when you imported the modules to your own app.
That often indicates duplicated module code.
Alternatively, you haven't imported the Show subprocedure to your form