CANNOT Publish Blazor WASM Apps to Folder using VS2026

[vsfeedback]

This issue has been moved from a ticket on Developer Community.

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[severity:I'm unable to use this version]
I can't use VS2026 to publish my blazor wasm app to a folder at all. In my attempts and experiments compared between vs2022 and vs2026, every version of dotnet blazor wasm app cannot work in vs2026, so I consider that is a bug of vs2026, not of dotnet10rc2. Both VS2022 and VS2026 are latest.
To reproduce the problem, follow this:

1. Install VS2022 and VS2026 with ASP.NET/Web Development feature.
2. Use VS2026 to make a new project from templete Blazor WebAssembly with dotnet8~dotnet10.
3. Go to VS2022 and open projects with dotnet8 or dotnet 9, and use the publish selection to publish this project to a folder, do same in VS2026, just have a more choice with project with dotnet10.
4. Compare the wwwroot _frameworks folder generated by vs2022 and vs2026.

After this you should find that VS2026 only has serveral files in _frameworks, and VS2022 has the whole runtime. I think because of this difference, Cloudflare Pages run into a different condition. The web app generated by VS2022 runs well but generated by VS2026 has errors about mono_wasm_load_runtime () failed or MIME type or others.
I find this by comparing a single project, Blazor WebAssembly App with dotnet9, published by VS2022 and VS2026 then upload to Cloudflare Pages. Only VS2022 could run well.

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Original Comments

Feedback Bot on 10/21/2025, 05:40 AM:

We have directed your feedback to the appropriate engineering team for further evaluation. The team will review the feedback and notify you about the next steps.

[Snowlights2022]

Hello, I made a ticket to VS2026 and I got this issue from email. But it was closed because my situation seems to be duplicate in the view of maintainers. But I may have several differences with #64049 .
I used .NET10rc2 to create and write Blazor wasm standalone project. And, I didn't got errors discussed in #64049.
All problems are related to Visual Studio function Publish To Folder originally. Due to VS2022 can't build any project targeted to dotnet10 or above, I can't do a test in dotnet10rc2 environment between VS2022 and VS2026. So I only give the test in dotnet9.

The new problem is, when I use dotnet cli to run or build or restore the project created in dotnet10rc2, I got some errors below:

C:\Program Files\dotnet\sdk\10.0.100-rc.2.25502.107\Sdks\Microsoft.NET.Sdk\targets\Microsoft.NET.Sdk.FrameworkReferenceResolution.targets(66,5): error NETSDK1226: 找不到删除包数据 .NETCoreApp 10.0 Microsoft.NETCore.App。 要忽略此错误，请将 AllowMissingPrunePackageData 设置为 true。

在 2.6 秒内还原 失败，出现 1 错误

But when I use VS2026 and just press F5,no matter debug mode or release mode, everything goes correctly. I build the project well and it runs well locally. Only when I publish the project to a specific folder and then upload the wwwroot folder to static webapp holders like Cloudflare Pages, Netlify, Vercel the error comes.

Would you re-consider and reopen this issue?

[Snowlights2022]

A bit more info:
I tried to reproduce the bug in #64049 , it occurs. But if I use VS2022, nothing wrong happens.

For a deploy runs without wrong, I did this:
Use VS2022 to create a new project in dotnet9 , and upload the repo to GitHub, then connect it with Cloudflare Pages. Write this in Build configuration:

curl -sSL https://dot.net/v1/dotnet-install.sh > dotnet-install.sh; chmod +x dotnet-install.sh; ./dotnet-install.sh -c 9.0 -InstallDir ./dotnet9; ./dotnet9/dotnet --version; ./dotnet9/dotnet publish -c Release -o output;

and choose output/wwwroot to be build output directory.
After this, the web page correctly run on static web app platform.