Error message:
TF212018: Work item tracking schema validation error: TF26177: The field TFS.Application.Name cannot be renamed from 'Application Name 2' to 'Application Name'.
TF212018: Work item tracking schema validation error: TF237094: Field name 'Application Name' is used by the field 'AppCompat.AppName', so it cannot be used by the field TFS.Application.Name2'.
Resolution:
1. Go to database Tfs_xxxDB
2. Open table dbo.Fields
3. Update the Name, NewName or ReferenceName