It is not possible to lock the business partner

What causes this issue?

It is currently not possible to lock the business partner. However, the
business partner must be locked, as a print date is to be stored in the
dunning history whilst printing the current print document. This is
necessary for print documents, in which invoicing has been dunned.
The EITERDK parallelization object is used in the <ZH>Mass Processing:
Bill Printout</> transaction (EA29). The parallelization takes place by
print document number. The system cannot lock the business partner if a
print document for the same business partner is being processed in a
different interval, and the business partner has been locked in this
print document.

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?

The current print document is processed at the next bill printout.
If n of the invoicing is either not dunned, or is very rarely dunned,
then it is worth using the <ZH>EITERDK</> parallelization object in the
<ZK>Mass Processing: Bill Printout</> transaction. Otherwise, you should
use the <ZH>BIPR_DX</> parallelization object, which parallelizes
according to business partner number.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.