Internal error calculating the internal key

What causes this issue?

An internal error has occurred when determining the internal key for an
iPPE object.

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?

INCLUDE PM_INTERNER_FEHLER OBJECT DOKU ID TX LANGUAGE EN

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.