When you try to load a file into a Revit model, the Schema Conflict message displays.
The file being loaded contains data in a schema. The Revit model contains another schema that has the same ID as the schema in the file. If the file is loaded, the existing data will be erased from the model.
Schemas should have unique IDs. This issue generally occurs only when a vendor reuses software code in an add-in.
Upgrade the Revit software to the latest update release (UR). These releases include software code that detects and removes the duplicate GUID storage correctly, avoiding this error when you try to update a family.