This CMN.ATO.IITR.601024 error appears when entries at D12 in the Deductions section create or increase a tax loss. Deductions can reduce your taxable income to zero, but they can't result in a loss.
Follow these steps to correct the D12 worksheet and lodge your return.
Open the Deductions section of the tax return.
Review the D12 worksheet and correct any entries that create or increase a tax loss:
Ensure deductions reduce taxable income to zero but do not result in a loss.
Revalidate the return and proceed with lodging it.