Hi again Kate
I would expect that if RoboHelp was aware of all the files,
all that you delete would appear in RoboHelp as being listed with
the red X. The red X signifies that RoboHelp is unable to find the
file. It's a clue to you, the help developer, that something is
amiss and needs to be addressed.
I'm not sure why some would just disappear while others would
behave as expected. Unless, of course, you had multiple copies of
certain files.
Cheers... Rick