I am a new owner of a Martin X200. The string that came with the bow
is 56inches and the bow is 60. The book said that the brace height should
be 8 to 8 3/4 inches , but mine is just over 9 . Will this be a problem?
Thanks to anyone who can help.

Somthing is outta whack somewhere, though I must admit I'm not at all sure what exactly....Probably the wrong string and/or cable length. Take it to a quality pro shop and have them look at it.