That's probably because there is a conflct with the firewall or an IP conflict between your PC and the cRIO. Make sure you disable the firewall first. If that doesn't work, reset the cRIO to reset the IP. There is a small Reset button on the cRIO that you need to press, then connect the cRIO to the PC and set the IP on the same subnet. Have a look at:
CompactRIO cRIO-9002/9004 Operating Instructions
