hi, I'm working on upgrading our xwiki form 1.0 to the 1.2m1, we using tomcat5.5 with postgresql8.0.8 database, everything configure in utf8, and we need keep the data. after I configure the hibernate, xwikicfg, webxml I start tomcat but I receive an exception when I getting into the page: type Exception report message description The server encountered an internal error () that prevented it from fulfilling this request. exception javax.servlet.ServletException: Error number 3 in 0: Could not initialize main XWiki context Wrapped Exception: Error number 3005 in 3: Migration failed Wrapped Exception: Error number 13021 in 13: Exception while constructing document archive Wrapped Exception: Error number 2002 in 2: Error parsing xml Wrapped Exception: Error on line 173 of document : Character reference "" is an invalid XML character. Nested exception: Character reference "" is an invalid XML character. org.apache.struts.action.RequestProcessor.processException(RequestProcessor.java:535) org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:433) org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:236) org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196) org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:414) javax.servlet.http.HttpServlet.service(HttpServlet.java:690) javax.servlet.http.HttpServlet.service(HttpServlet.java:803) com.xpn.xwiki.web.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:117) root cause com.xpn.xwiki.XWikiException: Error number 3 in 0: Could not initialize main XWiki context Wrapped Exception: Error number 3005 in 3: Migration failed Wrapped Exception: Error number 13021 in 13: Exception while constructing document archive Wrapped Exception: Error number 2002 in 2: Error parsing xml Wrapped Exception: Error on line 173 of document : Character reference "" is an invalid XML character. Nested exception: Character reference "" is an invalid XML character. com.xpn.xwiki.XWiki.getMainXWiki(XWiki.java:250) com.xpn.xwiki.XWiki.getXWiki(XWiki.java:400) com.xpn.xwiki.web.XWikiAction.execute(XWikiAction.java:94) org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:431) org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:236) org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196) org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:414) javax.servlet.http.HttpServlet.service(HttpServlet.java:690) javax.servlet.http.HttpServlet.service(HttpServlet.java:803) com.xpn.xwiki.web.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:117) note The full stack trace of the root cause is available in the Apache Tomcat/5.5 logs. it shows in the exception that there was migration problem with parsing some xml file on some symbols.... but I really do not know what does that mean and how I can solve it. anyone have ideas or samiliar problem experienced can give a help? regards, muzi