Add check for empty hierarchy and add not detected problems in diagnosis

Change-Id: I18348f969e4ede3386bc016988cc981a255d8c36
Signed-off-by: Denis Knoepfle <denis.knoepfle@sap.com>
Merge pull request #149 from DenisKnoepfle/master

Add check for empty hierarchy and add not detected problems in diagnosis