/// <summary>
/// X.
/// </summary>
public class K
{
}

SA1514: Element documentation header should be preceded by blank line is reported on the first /// in the file. Adding the new line resolves the diagnostic but instead raises SA1517: Code should not contain blank lines at start of file, leading to an infinite loop. Furthermore, the class has been intentionally declared in the global namespace, so there is no space for a namespace declaration