The error is being triggered incorrectly.
It will be corrected in the next version Access APS Tax 2026.3.0.
In the meantime, follow the below workaround:
Go to the Business worksheet.
Change the answer to ‘Did the taxpayer receive 80% of PSI services or more from one source?’ from Yes to No.
Tick the checkbox ‘Did the taxpayer pass the unrelated clients test?’.
Remove the tick from the next question: Did the taxpayer pass the employment test?
Go back to the question, Did the taxpayer receive 80% of PSI services or more from one source?’ and change the No back Yes.