Currency key cannot be determined for operating concerns

What causes this issue?

The assignment of currency keys for an operating concern is not unique
in table TKEBL.

System Response

Several entries exist for an operating concern in table TKEBL (same
entry in key field ERKRS and different entry in key field PALEDGER) for
which different currency keys are specified (in field WAERS).

How to fix this error?

Correct table TKEBL. All data records for the same operating concern
(field ERKRS) must have the same currency key (entry in field WAERS).
Restart program EWUORGLA.

Error message extract from SAP system. Copyright SAP SE.