&1: Fields in BSID do not match

What causes this issue?

For entry &V1& there is a mismatch between view BSID and the former
table (stored in BSID_BCK) in one of the following fields:
BUDAT (posting date)
BLDAT (document date)
DMBTR (amount in local currency)
KUNNR (customer number)
SAKNR (GL account number)
ZUONR (assignment number)
To compare the entries in your system, please compare the following
fields:
BKPF-BUDAT <-> BSID_BCK-BUDAT
BKPF-BLDAT <-> BSID_BCK-BLDAT
BSEG-DMBTR <-> BSID_BCK-DMBTR
BSEG-KUNNR <-> BSID_BCK-KUNNR
BSEG-SAKNR <-> BSID_BCK-SAKNR
BSEG-ZUONR <-> BSID_BCK-ZUONR

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?

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.