Microsoft.Azure.WebJobs.Extensions.Http: Could not load file or assembly

Question

I'm working in a virtual environment in VS Code and I can't understand why I'm getting this error:

[2022-07-19T10:00:31.580Z] A host error has occurred during startup operation '609dfded-e9f5-4fc4-b3a3-554bde11a415'.
[2022-07-19T10:00:31.582Z] Microsoft.Azure.WebJobs.Extensions.Http: Could not load file or assembly 'System.Net.Http.Formatting, Version=5.2.8.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'. The system cannot find the file specified.
Value cannot be null. (Parameter 'provider')

What should I check?

Answer 1

Rolled back nuget package Microsoft.NET.Sdk.Functions from 4.1.3 to 4.1.1 on the Azure functions Api project.

Rebuild solution.

Answer 2

This fixed it for me, hope it helps someone else

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

Taken from Unable to upgrade Azure Functions Core Tools, Exception "Cannot create instance of type 'NuGet.Versioning.VersionRange'"