Refresh using Project files on Microsoft SharePoint

Answer:

Sharepoint servers have a URL similar to this:  https://mycompany.sharepoint.com

Map a local drive to the SharePoint site:

1. Open Windows File Explorer.
2. Right-click  This PC or My Computer
3. Choose Map Network Drive.
4. In the Folder field, paste the URL of your SharePoint document library.  Ensure you are using the full URL, including the site and library name, for example:  https://yourdomain.sharepoint.com/sites/YourSite/Shared%20Documents. 
5. Select a drive letter for the mapped location.
6. Click Finish.

Refresh from a single schedule kept on SharePoint:

1. In Milestones, open the schedule to be refreshed and choose Connections | Refresh Previously Imported Project | Refresh from MPP file.
2. Using the mapped drive (above), locate the file and refresh the schedule (which is not tagged with nicknames.)

Refresh from a list of schedules kept on SharePoint:

1. Open the Milestones Professional schedule to be refreshed.
2. Build the refresh list (see below.)
3. Choose Connections | Refresh Previously Imported Project | Refresh from MPP file.

Add an MPP file on SharePoint to a refresh list

1. In Milestones, open the schedule to be refreshed and choose Connections | Refresh Previously Imported Project | Create/Edit Refresh List...
2. For each Microsoft Project schedule, pick Add Schedule (not Add Project Server Schedule.)  If the schedule already has nicknames, be sure to use the same nicknames for each schedule.
3. Click OK - Save Above Changes.