Claudia,
Several possible causes:
How did you bring the images and movies into RoboHelp? It
must be done within the RH project using either the Insert command
menu, or by importing as a baggage file. What you must not do is to
copy an image outside of RH and come back into RH to paste it.
Also, you cannot move images (or anything else [except a .css
file]) into the project folder from the Windows Explorer view.
Similarly, if you want to rearrange items in folders, you
cannot do it in Windows; move things between folders in the RH
project.
Maybe you already knew this, but I've seen inquiries here
resulting from this mistake.
Sometimes the RH housekeeping files get confused (some would
say corrupted), and need to be rebuilt. But the easiest thing to
try first is to bring each one into the project again. If you can
find it in one of the project folders, try using that one. Or go
back to the original location from which you originally imported
the file.
You may or may not get a warning that the item already exists
in the project, and asking if you want to overwrite it with the new
file. Yes, overwrite the phantom file with a new one. Sometimes
that will cause RH not to be confused any more.
If this doesn't bring them back to life, post back here, and
someone will point you to procedures for rebuilding project
maintenance files. This can get complicated, but it does work.
First try the re-import process.
Harvey