With the release of Microsoft Dynamics GP 2016 R2 it's time for a series of "hands on" posts where I go through the installation of all of it's components; the index for this series can be found here.
I've encountered this particular issue around the prerequisites so rarely, that I usually forget to mention it.
When installing the Web Services for Microsoft Dynamics GP there is a step where the SQL Server Connection Information is entered. This is the server where the Dynamics Security data will be stored.
You will receive the following message when clicking Next if the Windows user account you're logged in as, is not a SQL Server sysadmin: