Gtx 980ti can not Start cuda Debugging

Gtx 980Ti,I installed Cuda 7.028.but i can not Start Cuda Debugging on vs2012.
A CUDA context was created on a GPU that is not currently debuggable. Breakpoints will be disabled
Adapter:Gtx 980Ti

who can help me ? my nsight is 4.5

First thing: check that “debugging information” is available. Are you getting this message for a “debug version” of your VS2012 project? Are your kernels built with debug information?