If the web server is incorrectly configured you will find you can get to the XLCubed web application, but can not open any reports.
In this case please check:
XLCubed Web Edition Prerequisites - particularly the HTTP-Activation item.
Publishing Troubleshooting - the web.config may be incorrectly set up.
Web server memory usage - if this is above 95% then web service activation may be disabled by IIS. If this is the case an entry will be made in the windows event log.