Thank you. However, I'm still confused. I think I understand what you said here (but I could be wrong!).

My admin folder is not named admin but as far as I know I have put all the module admin files in the appropriate places within my admin (which is, of course, not named admin).

The path to my admin folder in admin/includes/configure.php is apparently correct because it has been working. In fact, I can make the admin area not work, work, not work, work, etc., simply by adding or removing the file I mentioned. It has to have something to do with this file or another file down the line connected with this one . . . somehow.

You said that "This means it is attempting to load in a file which doesn't exist." What file might that be? Is this file (the one I mentioned) or another one looking for admin/SOME_FILE and I need to edit it to look for MYADMIN/SOME_FILE instead?

I wish files could just tell me what it is they want! lol