How To Fix UD304 - Entity type & does not exist

SAP Error Message - Details

• Message type: E = Error

• Message class: UD - EDM - Enterprise Data Model

• Message number: 304

• Message text: Entity type & does not exist

What causes this issue?

It appears as if there is an inconsistency in the data model. The
entity types belonging to a relationship, specialization or
generalization cannot be read. An entity type no longer exists,
although it is still being used.
This inconsistency could have been caused by a faulty transport.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

Check your model.

Error message extract from SAP system. Copyright SAP SE.