I really didn't understand your last message. Also I didn't put a menu into another menu, not that I know of.
What I have notice also is that I get those errors in the Admin pages on my localhost but if I upload them unto the server I don't get those error messages at all:
So I not sure where there is a difference.
I attached a page where there is require once two times, could that be the issue?
Thanks for your help.