Login to your SharePoint Hosting Server as Farm Administrator.

Navigate to System Settings > Manage services on server verify the following Services are started.

• Managed Meta Data Web Service
• User Profile Service
• Search Applications (1. Search Host Controller Service, 2. “Search Query and Site Settings Service”, and 3. SharePoint Server Search)
• Office Online Server (formerly Office Web Apps server) must be installed and enabled.  This is to allow for the editing and preview of documents in the Document Management widget.
• Configure “Following” on your SharePoint Server – SharePoint Central Administration > Application Management > Manage service Applications > User Profile Service Application > Manage Following(under My Site Settings) - see this link for additional information - https://technet.microsoft.com/en-us/library/JJ219740.aspx
• For “Following” – Configure outgoing email settings – SharePoint Central Administration > System Settings > Configure outgoing email settings (under Email and Text Messages) - see this link for additional information - https://technet.microsoft.com/en-us/library/Cc263462.aspx

• From the Windows Start menu, click on “All Programs”, under Microsoft SharePoint 2016 Products, right click on “SharePoint 2016 Central Administration” and select “Run as administrator”.
• Navigate to “Application Management” > “Manage Service Application” (under Service Applications).

• • Verify that “AppManagement Service” is “Started”.
  • Verify that “Managed Metadata Service” is “Started”.
  • Verify that “User Profile Service Application” is “Started”
  • Verify that “Search Service Application” is “Started”

Note if these Services are not started then when you try and add the AppManager App to your site collection you will get an error: “Sorry, app is not support on your server”

• Navigate to – SharePoint Central Administration > Application Management > Manage service Applications highlight (do not click the title, click on the row) Managed Metadata Service. Then click on Properties in the Ribbon.
• Verify the following Check boxes are checked on the Managed Metadata Service Connection modal.
• Enable “Apps that require accessible internet facing endpoints” follow the following steps:
  1. Navigate to “Application Management” > “Managed web application”.
  2. Click on your SharePoint web application and then “Manage Features” (in the ribbon on the top).
  3. Verify that “Apps that require accessible internet facing endpoints” is set to ACTIVE.