Currency code of currency type &2 changed (see longtext)

What causes this issue?

You have changed the currency code of currency type &V3& (old value was
&V4&). This currency type is used in company code &V1&, ledger &V2&.
Postings exist in company code &V1&, ledger &V2&.
After this change, the existing journal entries are not longer valid.

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?

If the company code is already used in your production system, you need
to revoke this change.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.