Hi SE6516,
Welcome to the Community Forum! A possible reason why this happens is due to a corrupted draft pay run in the file. When this happens, we recommend starting a new pay run. To do this, go to the Create menu and choose Pay run. This will load the Create pay run page. Go back to Payroll > Pay runs > The page should now load.
If the issue persists, make sure to reach out to our support team directly. You can reach them on Live Chat via our virtual assistant, MYOB Support, or by submitting a support case via MYOB My Account.
Regards,
Earl