Remove project outputs? Project <installer project name> contains outputs of <project name> project you are removing. Would you like to remove them from <installer project name>?

The installer project specified contains outputs from the project you are removing. When you remove a project from an installer, you have the choice of removing the project's outputs or leaving them intact. If you remove the project but leave the project outputs, you will no longer be able to refresh the project outputs because the project is required to do this.