I also have this problem that was reported before.
using Xemacs [version 21.4.22; July 2010], from the menu I choose
edit, find. the message appears in the minibuffer "image instantiator
format is invalid in this locale..."
The find command on the edit menu doesn't find anything.
I don't use other languages so I think I compiled without Mule if that
has anything to do with it?
Can you suggest tests to find out what is happening?
the command: xemacs --vanilla gets the same error.