I get the message ''could not find the task 'build'" when I try to start my C# code

Question

I am new to C# and am learning using pluralsight

I have followed exactly what the tutorials are doing but have ran into a problem that the tutorial does not.

I have the simple ''Hello World'' program built when you make C# code via .Net

In Visual Studio Code, if go with Start Debugging or Start Without Debugging, the following error pops up

''could not find the task 'build'"

I then click on debug anyway then the following error shows up

launch:program dir \ < insert-project-name-here >.dll does not exist there is an option to open launch.json

the confusing thing is, the .dll file DOES exist...

Further, checking launch.json, I have the following:

{
  // Use IntelliSense to learn about possible attributes.
  // Hover to view descriptions of existing attributes.
  // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
  "version": "0.2.0",
  "configurations": [
    {
      "name": ".NET Core Launch (console)",
      "type": "coreclr",
      "request": "launch",
      "WARNING01": "*********************************************************************************",
      "WARNING02": "The C# extension was unable to automatically decode projects in the current",
      "WARNING03": "workspace to create a runnable launch.json file. A template launch.json file has",
      "WARNING04": "been created as a placeholder.",
      "WARNING05": "",
      "WARNING06": "If OmniSharp is currently unable to load your project, you can attempt to resolve",
      "WARNING07": "this by restoring any missing project dependencies (example: run 'dotnet restore')",
      "WARNING08": "and by fixing any reported errors from building the projects in your workspace.",
      "WARNING09": "If this allows OmniSharp to now load your project then --",
      "WARNING10": "  * Delete this file",
      "WARNING11": "  * Open the Visual Studio Code command palette (View->Command Palette)",
      "WARNING12": "  * run the command: '.NET: Generate Assets for Build and Debug'.",
      "WARNING13": "",
      "WARNING14": "If your project requires a more complex launch configuration, you may wish to delete",
      "WARNING15": "this configuration and pick a different template using the 'Add Configuration...'",
      "WARNING16": "button at the bottom of this file.",
      "WARNING17": "*********************************************************************************",
      "preLaunchTask": "build",
      "program": "${workspaceFolder}/bin/Debug/<insert-target-framework-here>/<insert-project-name-here>.dll",
      "args": ["link"],
      "cwd": "${workspaceFolder}",
      "console": "internalConsole",
      "stopAtEntry": false
    },
    {
      "name": ".NET Core Attach",
      "type": "coreclr",
      "request": "attach",
      "processId": "${command:pickProcess}"
    }
  ]
}

Answer 1

The easy way

In VS Code, after you've loaded the code base. Bring up the command pallet and enter > .NET Generate Assets for Build and Debug then hit return/enter.

This will force VS Code to recreate the launch.json and task.json files.

Keep an eye on the lower-left corner of the VS Code window for a toast message which looks like this:

and ensure that you click Yes

The complicated way

You need to alter the line in your task.json file which currently reads:

"program": "${workspaceFolder}/bin/Debug/<insert-target-framework-here>/<insert-project-name-here>.dll",

replacing <insert-target-framework-here> with the target framework moniker in your csproj, which might look like something similar to this:

<TargetFramework>netcoreapp2.1</TargetFramework>

You'll also need to replace the <insert-project-name-here>.dll string with the name of your produced DLL.