We have learnt (sadly the hard way) that you shouldn't reset an accrual scheme while the pay run is open. Doing this will mean that the accrual will then not work for the period you then attempt to process.
It is mentioned in the guide but given how much impact this has on the payroll, it would be great to see a warning pop up if someone tries to reset a scheme with a run open.
Either a warning, or ideally making it not possible in the same way that if a client tries to make an edit once they have submitted the payroll, it wont let them.