"This record in table hz_cust_accounts cannot be locked as it has been updated by another user." while updating Customer Account using HZ_CUST_ACCOUNT_V2PUB.UPDATE_CUST_ACCOUNT API in oracle apps

The error indicates that incorrect value of object_version_number is used in the TCA API.

Check object_version_number for the Customer Account which you are trying to update.

SELECT account_number, cust_account_id, object_version_number

FROM hz_cust_accounts

WHERE account_number in ('1234567890')

Pass the object_version_number returned from the above script to p_object_version_number and run the TCA API script.

This information you can find from Oracle Note, 1518466.1