cRIO doesn't detect modules

Title says it all. I have reimaged the cRIO and the modules say they are missing. I blew some air through the connection, and they still are missing. I tired switching cRIOs and switching modules, but it always says the modules are missing.

Any help? Thanks

Did you put the modules in the new locations as described in the 2012 control system getting started guide?

Make sure you only have one network adapter (use wired, turn off wireless). Make sure the IP address of your network adpater is correctly set and try a mask of 255.255.255.0.