An ATO rejection error with the prefix SBR.GEN.FAULT usually indicates an issue at the ATO.
Check on the Tax Agent Portal to see if the return was accepted. If the return was not accepted, try the lodgment again later.
If the return is rejected once more, view the lodgment summary report:
Log in to Tax.
Go to Reports, Lodgment Summary.
Locate the client and the rejected return.
Click on the rejected return to display the Transaction ID and Message ID number (at the bottom).
Contact the ATO's Registered agent phone line, 13 72 86, and request to speak to a second-tier consultant.
Provide the Transaction ID and Message ID along with the error information so they can advise you further.