Does this happen everytime you run the program, when you boot the RT system, or another case? It sounds like we should format the RT system. If your RT target is not a dual boot PXI you can format the target through MAX. Reboot your RT system in safe mode. On the host machine, right-click the target in remote systems and select Format Disk. After you format the disk you can reconfigure the RT target and install software to it.
After you get the controller restarted, try running the TCP/IP communication example that ships with the LabVIEW Real-Time module. If this program works correctly the original problem is somewhere in your software.
Jon S. National Instruments LabVIEW NXG Product Owner