Error while submitting Requisition via Rest API

This process was working fine till today.

But since the morning we are noticing Requisitions are failing from being submitted for Approval with the error below:

The Following error was encountered when an Oracle PR was submitted for approvals in Oracle.
You don't have permission to specify someone else as a requester. (POR-2011012)
You don't have the required permission to set the ItemUserOverrideFlag attribute to Y. (POR-2011263)

Any pointer will be helpful.

Thanks.