Hi JulieMac2,
Thanks for confirming and sorry for the late response. Can you please try turning off Setup > Preferences > Reports & Forms Tab "Include all YTD amounts and Entitlement Balances on Paycheque Stubs [System-wide]"
If the same issue you can try to put through a dummy paycheque with 1 hour and amount against each payroll category they have had in the past, then delete this pay. After this is done, the correct "employeepayrollcategoryregisters" are created in the database and payslips will send from that point on.
Please do let me know how you go on this.
Regards,
Earl