Same problem here, Scott. My upgrade from 3.8.1 first "updated the database", and then gave the same error sequence that you mentioned.
I tried to install a new copy, completely removing the old version, and it never starts listening on the admin port 9090. The message never comes up that says it is listening, anyways. At first, I hoped it was just not reporting the login URL anymore, but after checking, it really was not working.
There is definitely something wrong with the Windows 3.9.0 build.
