The planning record already exists

What causes this issue?

The CO interface is parametrized in such a way that you cannot
overwrite planned records that already exist (paramter UPDATE_VALUES =
SPACE). &v1& with key &v2& is to be transferred. However, this record
already exists in table &v3&.

System Response

Data has not been updated.
The planned record is written to the error log.

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?

Delete the corresponding record in manual planning or set the 'Reset
and Overwrite' flag when copying plan data (or the parameter
UPDATE_VALUES with programs that you have written yourself).

Error message extract from SAP system. Copyright SAP SE.