A required entry (&2 &3) is missing in customizing table &1

What causes this issue?

A customizing setting was to be imported from the database. However,
the required entry does not exist in the database.

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?

Contact your system administrators.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.