VScode新手问题，调试过程出现Unable to perform this action because the process is running.

调试在VScode下调试C#官网例子运行出现：Unable to perform this action because the process is running.停止debug后，扔出“..../Debug/netcoreapp1.1/projectApp.dll' has exited with code 0 (0x00000000).”错误请问怎么回事？我需要修改launch.json什么地方？launch.json：
{
    "version": "0.2.0",
    "configurations": [{
            "name": ".NET Core Launch (console)",
            "type": "coreclr",
            "request": "launch",
            "preLaunchTask": "build",
            "program": "${workspaceRoot}/bin/Debug/netcoreapp1.1/projectApp.dll",
            "args": [],
            "cwd": "${workspaceRoot}",
            "externalConsole": false,
            "stopAtEntry": false,
            "internalConsoleOptions": "openOnSessionStart"
        },
        {
            "name": ".NET Core Attach",
            "type": "coreclr",
            "request": "attach",
            "processId": "${command.pickProcess}"
        }
    ]
}