.NET 10 rc2 Blazor WebAssembly app does not work on Azure App Services

[zaksim]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

.NET 10.0.0-rc.2.25502.107 Blazor WebAssembly app does not work on Azure App Services.

Expected Behavior

Blazor WebAssembly app must be working on Azure App Services.

Steps To Reproduce

1. Create a new Project on Visual Studio 2026 Insiders [11111.16] with Blazor WebAssembly Standalone App template.
2. Create a new Azure App Services Web App

• Deployment : Code
• Runtime Stack : .NET 10 (LTS) (Preview)
• OS : Windows

3. Build and Deploy on Visual Studio to Azure App Services Web App

• Configuration : Release
• Target Framework : net10.0
• Deploy Mode : Self Contained
• Target Runtime : browser-wasm

Exceptions (if any)

No response

.NET Version

10.0.0-rc.2.25502.107

Anything else?

No response

[emu7800]

Experiencing the same issue but in a static-hosted environment. Reverting to RC1 resolved the issue. Seems the thumbprinting went haywire.

[David-Moreira]

Same issue, it works fine / as expected locally, dev build.
The issue is after deploying the app which has been built in release mode. I take it could be something in the release process, IL trimming, etc...
PS: In my case, it's deployed in a VM with a docker image, and just the blazor web assembly part of the web app crashes.

[YourYoungerBrothersPug]

Also experiencing this when running the container on an Unraid server. It works locally when running under debug, but not when I'm running it for production.

[David-Moreira]

I was just searching the issues, probably a duplicate for this: #64049

[ilonatommy]

If it's targeting net10, it's a duplicate of #63970 and is fixed in rtm.

[markburgessstl]

Same issue, running on Apache web server. Using RC1 fixed.

[e0548965]

Will there be a Service Release for .NET 10 RC2 to fix this? @ilonatommy or will we need to wait for November for the main release of .NET 10?

[ilonatommy]

Will there be a Service Release for .NET 10 RC2 to fix this? @ilonatommy or will we need to wait for November for the main release of .NET 10?

The fix will be available in GA and currently we are in process of looking for the best workaround for RC2.

[foximoxi]

How did this happen? Don't you test published application on maintenance 9.x version before release? RC is a different story.