Unable to run azure function locally when migrated to .net8

Abhijit Jadhav (INFOSYS LIMITED) 11 Microsoft Vendor

We are trying to migrate azure functions from .net6 to .net8. Post migration we get below error. We get below error in function app console when we run function in local.

"Could not load file or assembly 'Microsoft.Extensions.Configuration, Version=8.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60'. The system cannot find the file specified."

Function app uses Microsot.Extension.Configuration package.

Even after downgrading this package or other dependent packages we get this error.

MuthuKumaranMurugaachari-MSFT 22,246 Reputation points

2023-12-18T15:11:14.4833333+00:00

Abhijit Jadhav (INFOSYS LIMITED) Thanks for posting your question in Microsoft Q&A. Can you share function runtime (also core tools version), project reference (.csproj), full error message including stack trace? If possible, include code snippet, function.json so that it will be helpful in reproducing this issue.
Abhijit Jadhav (INFOSYS LIMITED) 11 Reputation points Microsoft Vendor

2023-12-18T17:21:16.29+00:00

Error - "Error configuring services in an external startup class. <FunctionName>: Could not load file or assembly 'Microsoft.Extensions.Configuration, Version=8.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60'. The system cannot find the file specified.

[2023-12-14T10:13:33.287Z] A host error has occurred during startup operation '892f4ce9-6c45-494d-9897-674ab718b1f0'."

Function version is 4. In Function app local settings FUNCTIONS_WORKER_RUNTIME is tried with 'dotnet' and 'dotnet-isolated' as well.

CSPROJ

Host
MuthuKumaranMurugaachari-MSFT 22,246 Reputation points

2023-12-18T20:10:08.0466667+00:00

Abhijit Jadhav (INFOSYS LIMITED) Unable to reproduce this issue at my end with the same packages. Can you share the code snippet, startup.cs along with full error message including stack trace?

I assume this reference Microsot.Extension.Configuration you mentioned is part of App Configuration logic? If so, I suggest review doc: Connect to an App Configuration store and add Microsoft.Azure.AppConfiguration.Functions.Worker package to the project and follow the initialization process as described.

Also, Microsoft.Azure.Functions.Extensions is not needed in isolated model and as per doc: Package references, there should not be any reference to this.

Let me know if it helps.
MuthuKumaranMurugaachari-MSFT 22,246 Reputation points

2023-12-21T14:09:53.48+00:00

Abhijit Jadhav (INFOSYS LIMITED) Just a follow up to see if the above comment helped with your question. If you still need assistance, let us know.
Gregory Baranowski 0 Reputation points

2024-03-20T14:22:21.36+00:00

I'm having the exact same issue as described above, with exactly same setup. I've found out that cleaning and rebuilding the project fixed this error.

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Unable to run azure function locally when migrated to .net8