AncestryDesk migration guide
How to find broken GEDCOM relationships
GEDCOM relationships are references between records. A family can point to a person that was omitted from the export, and a person can name a family record that no longer exists.
Index every level-zero record
Build separate sets for INDI and FAM cross-reference identifiers. Duplicate or malformed identifiers should be reviewed before relationship checks.
Check family member links
Validate every HUSB, WIFE and CHIL value against the individual index and report the exact family and source line for a missing target.
Check person-to-family links
Validate each FAMC and FAMS value against the family index. A one-sided relationship can explain missing branches after import.
Repair conservatively
Removing a reference to an absent record can be safe in a copy when the target truly is missing. Do not invent a replacement person or family.