I know that if you used a specific (won't name names here) activation workaround, and then later bought a license, that things would get all fouled up if you tried to uninstall the pirated copy and reinstall with your legit copy. There is a specific way, with the activation workaround tool, to remove your office to avoid this. I can easily see someone not doing that and then running into problems with their legal copy.
Not saying that is what is happening here by any means, in fact I'm not sure the error is even the same. Rather, I'm just further explaining why I posted what I did in post #3 of this thread.