Some of the reviewing features of Merops in the Microsoft Word plug-in read from the Standard Set so that the feature can work correctly for your preferences. For example, the Title Case feature reads from the Standard Set to determine if 4-letter prepositions should be capitalized.
If someone else processed the document for you, it's possible that you don't have the Standard Set in your Standard Sets folder. If that's the case, contact the person or organization that processed the file for you, ask them to send you the Standard Set, then import the Standard Set into your Standard Sets folder.