While attempting to run Payroll in a company that does not use Mekorma, we receive the warning: “ You can't use this feature until Mekorma is registered”

For the company in question where you intend to run Payroll using GP check printing, if the Mekorma Registration screen does not contain a key for Payroll, verify the Alternate/Modified Forms and Reports ID for ‘Payroll > Print Payroll Checks’ is set to Microsoft Dynamics GP, not Mekorma MICR.
 
Alternate/Modified Forms and Reports 
ID:  DEFAULTUSER (e.g.)
Product:  Mekorma MICR
Type: Windows
Series: All