I downloaded and updated our updatesite database and after restart the Xpages using Extlib doesn't work.
What caught my eye was that one of the "packs" was named "%feature name%" instead of the normal "Xpages extension Library feature".
This is also what seems to be missing.,
Error in logs:
2012-06-11 09:09:03 HTTP JVM: com.ibm.xsp.webapp.FacesServlet$ExtendedServletException: com.ibm.xsp.FacesExceptionEx: Cannot find the library com.ibm.xsp.extlib.library, required by the application/ourapp.nsf.
Reverting back to the 03-20 release fixed this, so something was bad in the latest release and should be fixed faster.
Regards
/Danne