Dynamics GP allows users to enter invoices through a number of different methods. When first accessing the invoicing windows in GP, users will often encounter a system alert warning them of the fact that they have multiple windows with which to enter the data. Without intervention, this warning will always appear for users moving forward.
To get rid of this warning, run your GP Utilities (from your Start menu). In the Additional Tasks window, select the ‘Remove SOP and Invoicing message’. Proceed to uncheck ‘Warn in Sales Order Processing’ & ‘Warn in Invoicing’. When complete, the warning will be gone forever.