I'm trying to run an Azure Function. After upgrading to .Net 6, debugging it locally with an updated version of Visual Studio 2022 gives me the following exception:

A host error has occurred during startup operation 'dca54039-23ee-4ec2-ad9d-9deafe1b2869'. [2022-09-08T07:07:05.464Z] Microsoft.Extensions.Configuration.Binder: Cannot create instance of type 'NuGet.Versioning.VersionRange' because it is missing a public parameterless constructor.

My co-workers do not get this error and it works great in production. The big difference we found was that they have a Core Tools Version that differs from mine.

• Mine: 4.0.3971
• Theirs: 4.0.4736

I believe the problem lies here, but besides trying to upgrade I also tried other things:

• Change to <AzureFunctionsVersion>v4</AzureFunctionsVersion>
• Update all nuget packages for .Net 6.
• Install latest version of Core Tool as mentioned on this page:

  Since then I've been trying to upgrade the Tools version. But here's the thing: even though func --version tells me I have 4.0.4736, the debug window still says 4.0.3971. I tried the following things:

  • I uninstalled everything and then installed the MSI again from the page mentioned above.
  • I ran npm i -g azure-functions-core-tools@4 in the Package Manager Console.
  • I uninstalled and re-installed using Chocolatey
  • I re-installed Visual Studio
  • I did the following things in an elevated powershell window:

  PS C:\Windows\system32> npm i -g azure-functions-core-tools@4 --unsafe-perm true

  changed 51 packages, and audited 52 packages in 18s found 0 vulnerabilities

  PS C:\Windows\system32> npm i -g [email protected] --unsafe-perm true

  changed 51 packages, and audited 52 packages in 26s found 0 vulnerabilities

  PS C:\Windows\system32> func --version 4.0.4736

  Nothing seems to help.

  CodePudding user response：

  The solution was:

  • Close Visual Studio
  • Delete folder C:\Users\***\AppData\Local\AzureFunctionsTools
  • Restart Visual Studio.
  • Launch Application, folder gets recreated.

  As soon as I had my co-worker review this question (to make sure I didn't post any vulnerabilities) he said "Oh, that other co-worker found a solution, you should delete C:\Users\***\AppData\Local\AzureFunctionsTools and you're good to go"

  So I did.

  And it works right away.