More from the GP Support Team on Microsoft Dynamics GP 2015 R2 – Upgrade Troubleshooting
Microsoft Dynamics GP 2015 R2 – Upgrade Troubleshooting – Microsoft Dynamics GP Community
Install, Upgrade & AdminMicrosoft & the GP EcosystemGP 2015
Archived post from 2015. Dynamics GP and the links it points to have changed since; check current documentation before relying on version-specific steps.