XML parse Error

Hello, to deploy a struts application I use Tomcat 5.0but I becom folowing Error Parse Error at line 539 column 15: Document is invalid: no grammar found.org.xml.sax.SAXParseException: Document is invalid: no grammar found.wht is wrongthanks
[290 byte] By [the_Orienta] at [2007-10-1 8:28:08]
# 1
please help meThis ErrorParse Error at line 539 column 15: Document root element "struts-config", must match DOCTYPE root "null".
the_Orienta at 2007-7-9 22:31:01 > top of Java-index,Enterprise & Remote Computing,Web Tier APIs...