Unable start the function app project in the debugger

Question

Unable start the function app project in the debugger

Robi Indra Das 30

Attempting exercise at https://learn.microsoft.com/en-us/training/modules/develop-azure-functions/5-create-function-visual-studio-code Under run the function locally, Step 2 says: Press F5 to start the function app project in the debugger. When I press F5, after it builds, it shows the error [2024-01-28T02:31:28.015Z] A host error has occurred during startup operation '49001b8d-a2aa-45b0-8b2f-6f533b2586fb'. [2024-01-28T02:31:28.037Z] 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')[2024-01-28T02:31:29.272Z] A host error has occurred during startup operation '9f9e2d03-ac6f-4757-94c7-0322d350cff0'.

pnaroju 3,165 Reputation points Microsoft External Staff

2024-01-29T02:15:49.2766667+00:00

Hi Robi Indra Das,

Thank you for reaching out to us on Microsoft Q&A forum.

We are working on it and will update you soon.

Thank you.
AmaranS 7,270 Reputation points Microsoft External Staff

2024-01-29T09:04:03.2+00:00
Hi Robi Indra Das,

Thank you for reaching out to Microsoft Q & A forum.

It seems like the error is related to the missing assembly 'System.Net.Http.Formatting' with a specific version. To resolve this issue, you can try the following steps:

1.Try updating the 'System.Net.Http.Formatting' package to the required version. You can do this using the following command in the terminal:

dotnet add package System.Net.Http.Formatting --version 5.2.8

[NOTE: Please review the updated document before proceeding with the update to this version]

2.After updating the packages, clean and rebuild your project to ensure that the changes take effect.

3.Double-check that the assembly reference is correctly added in your project file. Ensure that the version mentioned in your project file matches the version specified in the error message. **

NOTE:** "Please follow the steps outlined in the newly updated document to complete the exercise. In the revised document, you'll find an example video that provides additional guidance. Pay special attention to the section regarding 'System.Net.Http.Formatting.' Update the version based on the instructions in the video; this adjustment might resolve the error you encountered. **

UPDATED DOC: https://learn.microsoft.com/en-us/azure/azure-functions/create-first-function-vs-code-csharp

Additional Info: https://learn.microsoft.com/en-us/azure/azure-functions/functions-develop-vs-code?tabs=node-v3%2Cpython-v2%2Cisolated-process&pivots=programming-language-csharp#debugging-functions-locally

If you encounter the same error even after completing the steps outlined in the updated document, feel free to contact us for further assistance.

Thank you.

Robi Indra Das 30

I was unable to follow your suggestion. When trying to add System.Net.Http.Formatting it failed with errors. Here is the output:

PS C:\Temp\TestFunc> dotnet add package System.Net.Http.Formatting --version 5.2.8
  Determining projects to restore...
  Writing C:\Users\Administrator\AppData\Local\Temp\tmpeal5px.tmp
info : X.509 certificate chain validation will use the default trust store selected by .NET for code signing.
info : X.509 certificate chain validation will use the default trust store selected by .NET for timestamping.
info : Adding PackageReference for package 'System.Net.Http.Formatting' into project 'C:\Temp\TestFunc\TestFunc.csproj'.
info : Restoring packages for C:\Temp\TestFunc\TestFunc.csproj...
info :   GET https://api.nuget.org/v3-flatcontainer/system.net.http.formatting/index.json
info :   OK https://api.nuget.org/v3-flatcontainer/system.net.http.formatting/index.json 86ms
error: NU1102: Unable to find package System.Net.Http.Formatting with version (>= 5.2.8)
error:   - Found 3 version(s) in nuget.org [ Nearest version: 4.0.20710 ]
error:   - Found 0 version(s) in Microsoft Visual Studio Offline Packages
info :   CACHE https://api.nuget.org/v3/vulnerabilities/index.json
info :   CACHE https://api.nuget.org/v3-vulnerabilities/2024.01.24.05.35.05/vulnerability.base.json
info :   CACHE https://api.nuget.org/v3-vulnerabilities/2024.01.24.05.35.05/2024.01.29.23.36.04/vulnerability.update.json
error: Package 'System.Net.Http.Formatting' is incompatible with 'all' frameworks in project 'C:\Temp\TestFunc\TestFunc.csproj'.
PS C:\Temp\TestFunc>

Here is the csproj file that was generated by visual studio code:

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFramework>net6.0</TargetFramework>
    <AzureFunctionsVersion>v4</AzureFunctionsVersion>
  </PropertyGroup>
  <ItemGroup>
    <PackageReference Include="Microsoft.NET.Sdk.Functions" Version="4.2.0" />
  </ItemGroup>
  <ItemGroup>
    <None Update="host.json">
      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
    </None>
    <None Update="local.settings.json">
      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
      <CopyToPublishDirectory>Never</CopyToPublishDirectory>
    </None>
  </ItemGroup>
</Project>

Here is the version information from Visual Studio Code:

Version: 1.85.2 (system setup)
Commit: 8b3775030ed1a69b13e4f4c628c612102e30a681
Date: 2024-01-18T06:40:10.514Z
Electron: 25.9.7
ElectronBuildId: 26354273
Chromium: 114.0.5735.289
Node.js: 18.15.0
V8: 11.4.183.29-electron.0
OS: Windows_NT x64 10.0.19045

AmaranS 7,270 Reputation points Microsoft External Staff

2024-01-30T03:50:12.5666667+00:00
Hi Robi Indra Das,

Whenever I have a NuGet error such as these I usually take these steps:

1. Go to the packages folder in the Windows Explorer and delete it.

2.Open Visual Studio and Go to Tools > Library Package Manager > Package Manager

Settings and under the Package Manager item on the left hand side there is a "Clear Package Cache" button. Click this button and make sure that the check box for "Allow NuGet to download missing packages during build" is checked.

3.Clean the solution

4.Then right click the solution in the Solution Explorer and enable NuGet Package Restore

5.Build the solution

6.Restart Visual Studio I installed the latest version of NuGet package Microsoft.AspNet.WebApi.Client and then uninstalled System.Net.Http.Formatting. After uninstalling package System.Net.Http.Formatting,

Tools / NuGet Package Manager / Package Manager Console

Update-Package -ProjectName MyProjectName -reinstall

Remove all code references to System.Net.* in the package window,

Install-Package Microsoft.AspNet.WebApi.Client

Clean and rebuild your project

Additionally info:

VS2019: Tools -> Nuget Package Manager -> Package Manager Setting -> in Package Restore section, check 2 options. After that, go to project packages folder and delete all child folders inside (for no longer any error) Then Rebuild solution, Nuget will redownload all packages and project should run without any reference.

If you encounter any future issues, please feel free to contact us, and we will be pleased to assist you further.
AmaranS 7,270 Reputation points Microsoft External Staff

2024-01-31T02:30:16.1833333+00:00

@Robi Indra Das Just checking in to see if you had got a chance to see the previous comment. Has your issue been resolved? If you are still experiencing the problem, please inform us. We are happy to help you.
AmaranS 7,270 Reputation points Microsoft External Staff

2024-02-01T03:54:47.7333333+00:00

Hi Robi Indra Das,Just checking in to see if you had got a chance to see the previous comment. Has your issue been resolved? If you are still experiencing the problem, please inform us. We are happy to help you.
Robi Indra Das 30 Reputation points

2024-02-01T05:54:17.01+00:00

This has been put on hold until March.
AmaranS 7,270 Reputation points Microsoft External Staff

2024-02-01T07:44:44.4566667+00:00

Hi Robi Indra Das,

Thanks for your response.If you are still experiencing the problem, please inform us. We are happy to help you. Thank you.

Your answer

pnaroju 3,165 Reputation points Microsoft External Staff

2024-01-29T02:15:49.2766667+00:00

Hi Robi Indra Das,

Thank you for reaching out to us on Microsoft Q&A forum.

We are working on it and will update you soon.

Thank you.
AmaranS 7,270 Reputation points Microsoft External Staff

2024-01-29T09:04:03.2+00:00

Hi Robi Indra Das,

Thank you for reaching out to Microsoft Q & A forum.

It seems like the error is related to the missing assembly 'System.Net.Http.Formatting' with a specific version. To resolve this issue, you can try the following steps:

1.Try updating the 'System.Net.Http.Formatting' package to the required version. You can do this using the following command in the terminal:

dotnet add package System.Net.Http.Formatting --version 5.2.8

[NOTE: Please review the updated document before proceeding with the update to this version]

2.After updating the packages, clean and rebuild your project to ensure that the changes take effect.

3.Double-check that the assembly reference is correctly added in your project file. Ensure that the version mentioned in your project file matches the version specified in the error message. **

NOTE:** "Please follow the steps outlined in the newly updated document to complete the exercise. In the revised document, you'll find an example video that provides additional guidance. Pay special attention to the section regarding 'System.Net.Http.Formatting.' Update the version based on the instructions in the video; this adjustment might resolve the error you encountered. **

UPDATED DOC: https://learn.microsoft.com/en-us/azure/azure-functions/create-first-function-vs-code-csharp

Additional Info: https://learn.microsoft.com/en-us/azure/azure-functions/functions-develop-vs-code?tabs=node-v3%2Cpython-v2%2Cisolated-process&pivots=programming-language-csharp#debugging-functions-locally

If you encounter the same error even after completing the steps outlined in the updated document, feel free to contact us for further assistance.

Thank you.
AmaranS 7,270 Reputation points Microsoft External Staff

2024-01-30T03:50:12.5666667+00:00

Hi Robi Indra Das,

Whenever I have a NuGet error such as these I usually take these steps:

1. Go to the packages folder in the Windows Explorer and delete it.

2.Open Visual Studio and Go to Tools > Library Package Manager > Package Manager

Settings and under the Package Manager item on the left hand side there is a "Clear Package Cache" button. Click this button and make sure that the check box for "Allow NuGet to download missing packages during build" is checked.

3.Clean the solution

4.Then right click the solution in the Solution Explorer and enable NuGet Package Restore

5.Build the solution

6.Restart Visual Studio I installed the latest version of NuGet package Microsoft.AspNet.WebApi.Client and then uninstalled System.Net.Http.Formatting. After uninstalling package System.Net.Http.Formatting,

Tools / NuGet Package Manager / Package Manager Console

Update-Package -ProjectName MyProjectName -reinstall

Remove all code references to System.Net.* in the package window,

Install-Package Microsoft.AspNet.WebApi.Client

Clean and rebuild your project

Additionally info:

VS2019: Tools -> Nuget Package Manager -> Package Manager Setting -> in Package Restore section, check 2 options. After that, go to project packages folder and delete all child folders inside (for no longer any error) Then Rebuild solution, Nuget will redownload all packages and project should run without any reference.

If you encounter any future issues, please feel free to contact us, and we will be pleased to assist you further.
AmaranS 7,270 Reputation points Microsoft External Staff

2024-01-31T02:30:16.1833333+00:00

@Robi Indra Das Just checking in to see if you had got a chance to see the previous comment. Has your issue been resolved? If you are still experiencing the problem, please inform us. We are happy to help you.
AmaranS 7,270 Reputation points Microsoft External Staff

2024-02-01T03:54:47.7333333+00:00

Hi Robi Indra Das,Just checking in to see if you had got a chance to see the previous comment. Has your issue been resolved? If you are still experiencing the problem, please inform us. We are happy to help you.
Robi Indra Das 30 Reputation points

2024-02-01T05:54:17.01+00:00

This has been put on hold until March.
AmaranS 7,270 Reputation points Microsoft External Staff

2024-02-01T07:44:44.4566667+00:00

Hi Robi Indra Das,

Thanks for your response.If you are still experiencing the problem, please inform us. We are happy to help you. Thank you.

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Unable start the function app project in the debugger

Your answer