Postings to account & (company code &) are only possible in currency &

What causes this issue?

G/L account "&v1&" is managed in "&v3&". For this reason, it is not
possible to post amounts in "&v4&".

System Response

The data canot be updated.

How to fix this error?

If you want to post a gain or loss from exchange rate fluctuation to a
foreign exchange account, you must use the <LS>Foreign currency
valuation</> function.
<DS:TRAN.F-05>Proceed</>
If you do not want to do this, correct currency key "&v3&" in the
master record of G/L account "&v1&" in company code "&v2&".
<DS:TRAN.FS02>Proceed</>

Error message extract from SAP system. Copyright SAP SE.