Aborting substack opening from within preOpenStack?

[Dr. Hawkins]

When some of my substacks are called to open, I need to check that
conditions are ready.

so

if badCondition then
answer "You can't do this yet because blah blah blah!"
close this stack
end if


But this doesn't seem to stop openStack from getting called; I thought it
did.

How do I cause the entire stack opening to abort from within preOpenStack?

And on that line, I'm tracking a bug that is messing with opening a card
with a datagrid.  Apparently my grey column problem is linked to a livecode
supplied script that tries to "set the text of me to empty", but I don't
have it cornered yet.  But these seme related.

-- 
Dr. Richard E. Hawkins, Esq.
(702) 508-8462