When switching from an old version of word to a newer version especially when there are multiple version differences you may have to resave your docs to the new version before you use them.
If you see a "compatibility mode" at the top of your word doc. You may need to convert the doc by doing the following.
1. Go to file at top.
2. Click the Convers button.
3. Once converted you need to resave the document. Go back to file and click "Save"