Unable to build project output group Content Files from

Problem

When you try to build a deployment package in Visual Studio .NET, you may receive the following error message:

Unable to build project output group 'Content Files from WebApplicationName'

Note: In this error message, WebApplicationName is a placeholder for the name of the Web application that is part of the project.

Solution

This behavior occurs if dependency files for the Web application are missing from project.

To resolve this behavior, you can replace any missing dependency files, or you can remove the file that requires them if the project does not require that file.