Unknown Error: 0x800700c1, While debugging .net Core 3.0 API in VS Code

I am building a .Net Core API with 3.0.

It was all working well before a week, and for a couple of days it is now throwing a strange Error when I try to debug, as shown in the following Screenshot on the bottom left corner.

And the debugger is stopped at this point.

Following is my .vscode > launch.jason file

{
"version": "0.2.0",
   "configurations": [
        {
            "name": ".NET Core Launch (web)",
            "type": "coreclr",
            "request": "launch",
            "preLaunchTask": "build",
            // If you have changed target frameworks, make sure to update the program path.
            "program": "${workspaceFolder}/bin/Debug/netcoreapp3.0/WebApi.dll",
            "args": [],
            "cwd": "${workspaceFolder}",
            "stopAtEntry": false,
            // Enable launching a web browser when ASP.NET Core starts. For more information: https://aka.ms/VSCode-CS-LaunchJson-WebBrowser
            "serverReadyAction": {
                "action": "openExternally",
                "pattern": "\\bNow listening on:\\s+(https?://\\S+)"
            },
            "env": {
                "ASPNETCORE_ENVIRONMENT": "Development"
            },
            "sourceFileMap": {
                "/Views": "${workspaceFolder}/Views"
            }
        },
        {
            "name": ".NET Core Attach",
            "type": "coreclr",
            "request": "attach",
            "processId": "${command:pickProcess}"
        }
    ]
}

Following is my WebApi.csproj

<Project Sdk="Microsoft.NET.Sdk.Web">
  <PropertyGroup>
    <TargetFramework>netcoreapp3.0</TargetFramework>
  </PropertyGroup>
  <ItemGroup>
    <PackageReference Include="AutoMapper" Version="9.0.0" />
    <PackageReference Include="AutoMapper.Extensions.Microsoft.DependencyInjection" Version="7.0.0" />
    <PackageReference Include="Microsoft.AspNetCore.Authentication.JwtBearer" Version="3.0.0" />
    <PackageReference Include="Microsoft.AspNetCore.Cors" Version="2.2.0" />
    <PackageReference Include="Microsoft.EntityFrameworkCore" Version="3.0.0" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="3.0.0">
      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
      <PrivateAssets>all</PrivateAssets>
    </PackageReference>
    <PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite" Version="3.0.0" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="3.0.0" />
    <PackageReference Include="System.IdentityModel.Tokens.Jwt" Version="5.5.0" />
  </ItemGroup>
</Project>

I tried re-running the project deleting Debug folder, but didn't work out.

Had the same issue. The error means you sent the debugger a file that is not an executable. Try and verify that the path to executable you're trying to debug is correctly configured at launch.json (program property).