Whenever a record is in the process of being created or updated in Salesforce, the record is temporarily locked so that no other processes will modify the record simultaneously. Since LeanData runs natively on Salesforce, it is also subject to this limitation.
If you see this error, it only means that multiple operations are attempting to process a record. LeanData is not necessarily involved.
If a LeanData operation was stopped due to this error, LeanData will automatically retry the action at a later time.
For more information on this error, please see the below Salesforce Knowledge Article: