[MiseValidator] Exception message: Could not load file or assembly 'Microsoft.IdentityModel.Logging, Version=8.3.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'. The system cannot find the file specified.

[hverma2587]

I am using IMiseValidator to validate the tokens. I have the below code but when running the application I am getting the File Not Found error

[MiseValidator] Exception message: Could not load file or assembly 'Microsoft.IdentityModel.Logging, Version=8.3.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'. The system cannot find the file specified.

Code :
Item.TrackTrace($"[MiseValidator] Initialising Mise handler.");
IMiseHandler miseHandler = MiseStandard.Instance.GetMiseHandler(); -> Getting error here.

I have added Nuget Package, updated the CSProj file. Also tried Creating a new app.config and package.config file but still could not solve the issue.
Tried using _FunctionsSkipCleanOutput also.

Can anyone help on this.

Thanks

[Frulfump]

What version of Functions are you using, Isolated or In-Process? (Often times these type of load issues happen with the in-process model). And what version of .NET are you using?
app.config and package.config usually means you are using .NET Framework as the current standard with modern .NET is appsetttings.json and just having package references in the csproj themselves. Microsoft.IdentityModel.Logging, Version=8.3.0.0 sounds quite recent (8.12.1 is the latest apparently https://www.nuget.org/packages/Microsoft.IdentityModel.Logging).
Is it happening both locally and in Azure?
Which runtime version of functions are you on?

There's another issue open here where they are having problems with loading Microsoft.Identity.Model.Logging #8587 maybe some of the tips in there could help you?

Does running dotnet nuget why Microsoft.IdentityModel.Logging if you are using .NET 8 SDK 8.0.400+ tell you anything about which libraries is pulling in Microsoft.IdentityModel.Logging?
https://learn.microsoft.com/en-us/dotnet/core/tools/dotnet-nuget-why

If you are using In-Process .NET Functions the support for that is ending on November 10:th 2026 so it's time to plan for a migration to the isolated model is that an alternative here (it currently supports .NET Framework 4.8, .NET 8 and 9 https://learn.microsoft.com/en-us/azure/azure-functions/dotnet-isolated-process-guide?tabs=hostbuilder%2Cwindows#supported-versions)?

https://azure.microsoft.com/en-us/updates?id=retirement-support-for-the-inprocess-model-for-net-apps-in-azure-functions-ends-10-november-2026

It's probably best to open a support ticket with Microsoft so they can help you out properly.

[hverma2587]

I am using In-Proc and netframework is net472.
The error is coming locally and while deploying as StaticWebApp.
I am not using Azure Function. Initailly we were using Azure Functions and did not find any issue. When we tried to move the code to our local from that point we are getting error.

Just to bring to Notice we are using Net8.0 for all projects except 1 which is referenced in Net8.0 but is setup on Net472.