SYMPTOM:
When updating Schema in 3-tier in Strategy Developer, the following error appears:

Error(s) occurred while loading schema: DSSSQLEngine: Schema loading error: Population Exception: The object shown in the following hierarchy no longer exists in schema: -Relation-Relationship The object definition is incomplete or inconsistent. Error(s) occurred while loading schema: 54

Specified cast is not valid

ACTION:
Define a relationship table if missing. Contact Strategy Technical Support if you need help to identify the faulty attribute(s).
RELATED KB ARTICLES:
KB42571