The URL "nrpc:///__8525744d0049743e/site.xml" refers to a the database with replica ID 8525744d:0049743e. This is the update site database. If you have made a copy of the update site, it will have a new replica ID and you will have to adjust the URLs. If you haven't yet installed the update site (because you couldn't extract it) then it won't work either.
If you select the update site from the workspace, then click Actions->Show URLs, it will display what should be the correct URL to use.
Cheers,
Jo