code checking error

      Validation Output: 1 Error

   1. Error /Line 1, Column 1/: end of document in prolog

      |*<*!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.o...|

http://sodavending.vendingworld.com/canenergy.php
I get this same error on all my pages that I check, the code has not 
changed and they used to be error free


NOTE: Whenever possible, give the address of the document you were 
checking.