Connection to the Nsight monitor on 'localhost' failed. The application is in break mode.

I use GTX1060, vs2015, and Nsight5.2, my system is win10. Before i set a breakpoint inside a kernel function and Start CUDA Debugging under Nsight, it shows the error of “The application is in break mode…”. But at least it can connect to localhost. Today when i try again, it can not connect to localhost anymore.Does anyone know solutions to either problem?