#3 RDF browser does not display URL information

[Frank Breitling]

After installation I opened /usr/local/oat-2.6/rdfbrowser/index.html in firefox. I saw a window with "Ajax call in process" and after clicking "ok" I receive an JavaScript error.
Firebug shows me:

file:///sparql?ini&&oatSecurityCookie=09641577996892836

[Exception... "Component returned failure code: 0x80520012 (NS_ERROR_FILE_NOT_FOUND) [nsIXMLHttpRequest.send]" nsresult: "0x80520012 (NS_ERROR_FILE_NOT_FOUND)" location: "JS frame :: javascript: eval(firebugTemp); :: anonymous :: line 1" data: no]

Thereafter, I do not see any RDF information for URIs, although these URIs work fine with the online demo at http://demo.openlinksw.com/DAV/JS/rdfbrowser/index.html.