Pegging area locked by user &1

What causes this issue?

Two parallel transactions are attempting to create a pegging area for
the same combination of product, location, planning version, and account
assignment. The pegging area is locked.

System Response

The transaction is terminated.

How to fix this error?

Execute the transaction again later by which time the pegging area will
have been created by the parallel transaction.

Procedure for System Administrators

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

Error message extract from SAP system. Copyright SAP SE.