Steps to reproduce:
Go to Administration -> Pedigree Editor
Change the Date Display Format to dd-mm-yyyy (see screenshot) and save the settings.
Create a new family
Edit the new family using the XWiki object editor, e.g. http://localhost:8080/edit/Families/FAM0000001?editor=object
Find the PedigreeClass object
In the "Pedigree Data" property, paste the contents of
Save the family
Try opening the family pedigree in the pedigree editor. The pedigree is rendered without lines connecting the nodes, and some nodes are missing. (See attached screenshot).