Update problem in line item table &

What causes this issue?

The system attempted to update one or more documents in table &V1&. This
attempt failed due to a problem when inserting line items.
It is highly likely that this runtime error was caused by a DUPREC
problem. The system attempted to insert a line into line item table &V1&
for which a line with the same unique key already exists (duplicate
record).
Normally, the SL-based line item tables must have unique keys for the
following combinations:
Key 1:
RCLNT
GL_SIRID

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Key 2:
RCLNT
DOCNR
RYEAR
DOCCT
RBUKRS
RLDNR
DOCLN
The following causes for a DUPREC error are possible in this case:
The number range objects for the DOCNR or GL_SIRID fields (if available)
are not maintained correctly.
Note here that the number range objects for the DOCNR field can differ
according to application.
The GL_SIRID field (if available) is normally assigned to the number
range object GL_RECID.
Documents or line items were subsequently posted that have already been
posted once before or that were not previously deleted.
An additional customer-specific UNIQUE index was created.

System Response

The update was terminated with a runtime error.

How to fix this error?

Check whether the line item table &V1& contains one or more data records
for the document(s) listed below. The next steps for this procedure are
described in SAP Note 62150.
<ZH>Analysis information:</>
The system attempted to update the following documents (ledger/company
code/year/SL document number):
&V2&
&V3&
The system attempted to update the following GL_RECID keys (min./max.
values):
&V4&
If the analysis shows that the problem is not a duplicate record,
further causes for the runtime error (such as problems in the database
system) must be analyzed.

Error message extract from SAP system. Copyright SAP SE.