Yes, Office, while being the standard, is pricey. I am lucky enough to get 10 for free. I installed Office 16, and there wad no benefit.
So, that would not be your issue. I guess it's good for people to know that the 64-bit version of Word doesn't "play well" with Adobe. But, I guess when you pay a mortgage payment for both, why should they.
With your problem, it's hard, because it is sporadic, which is the hardest thing to troubleshoot.
This is a crazy question. Have you talked with Adobe support?