Visual Studio Insiders blocks ASP.NET builds on unmatched scoped CSS endpoints #70014

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

[regression] [worked-in:VS 2026 Insiders 12224.323]
After Visual Studio Insiders 2026 I'm not able to compile the application because of the issue:

the following scoped css bundles do not have matching endpoints: _framework/microsoft.net.sdk.blazorweb.dotnetwatch#[.{fingerprint}]!.lib.module.js

If I create the new ASP.NET Web API project I'm getting the same issue.

IntegraService.csproj

I'm attaching .csproj which has problem with this.
After rollback everything works fine.

Original Comments

Feedback Bot on 15/10/2026, 07:45 AM:

Based on similar issues resolved with Microsoft in the last 6 months, the following can help resolve this issue faster.

Possible workarounds

Continue using the previous Visual Studio version that builds the project successfully, as reported. Also test the latest available Visual Studio Insiders build to determine whether the regression has been corrected.

If not already included, please provide:

Detected: VS: Visual Studio Insiders 2026, Project type: ASP.NET Web API, Category: .NET

• What exact Visual Studio version/build reproduces the issue, and which previous version works?
• What .NET SDK version is installed, and is a global.json present? Please include its contents if applicable.
• Does the failure occur with both Build and Rebuild, and does dotnet build from a command prompt fail with the same message?
• Please provide the complete build output and, if possible, a binary log from the failing build.
• Please confirm the exact steps to reproduce this in the new ASP.NET Web API project and whether it reproduces every time.

Feedback Bot on 15/10/2026, 09:18 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.

Gyorgy Koszeg on 19/10/2026, 02:42 PM:

I had the same issue. Confirming that a rollback to 12224.323 solves the problem.