Solution:
1. You can enable the Servers button assigning any of these three user rights:
Maintenance - File Objects, File Locations - Add
Maintenance - File Objects, File Locations - Edit
Maintenance - File Objects, User File Directories - Edit
2. Make sure to reload rights from Tools | Re-cache Code or Logoff and log in again.
Note: The only way you will have the Servers button disabled is to take away all 3 rights above.