[grantf]

I just had this error as well. It turns out that I was trying to debug the wrong project. Bring up the "Debug" dialog by right-clicking on your project in the project explorer and click "Debug Kernel Task." In the "Downloads" tab, make sure that the file that is being transferred is the .out file associated with your project. Make sure that the other settings you specify conform to the instructions in the WPI C/C++ Getting Started Guide in the section titled "Debugging your robot program" (page 11).

Good luck, and please reply if this fixed your problem or not so others can benefit too!