The error seemed quite clear: Cannot read configuration file due to insufficient permissions. Just to be sure, I added the user MDSAppPool – created in the MDS Configuration Manager for the MDS Application Pool – to the Administrators group on the machine. A brute-force solution, but since it’s on my own machine for demo purposes, I didn’t really care. Of course it didn’t work. Then I assigned full control permissions for the MDSAppPool user on the folder C:\Program Files\Microsoft SQL Server\130\Master Data Services. Didn’t work. Used the browser in Administrator modus. Also didn’t work. Checked IIS settings and discovered that Windows Authentication was not enabled. So I enable it, but the error persists. This is the point where it all starts to get frustrating. Adding MDSAppPool to the IIS_IUSRS group doesn’t work. Giving that group full control on the MDS directory either.
Read on for the solution.