Have you ever wondered what the key icon appearing on a specific file or folder in the project explorer actually means? If you don't know what it means, it could indicate you are in trouble. The key icon indicates one or several build settings for the related file or folder differs from the project's overall build settings. If you have set specific build settings for the file or folder, then the key icon is just a friendly reminder so you do not forget this.
If you are not aware of specific build settings for the file or folder, then this could lead to frustration and problems as the project may not build or execute as intended. In this blog post, I will explain how to resolve these problems.