If anyone is using Exchange 2010 and OWA with Update Rollup 2 installed, they might be having some issues.
One issue we came across, was that OWA was not being displayed after login. The current setup was Router<->TMG Server<->Exchange. As you can see, we have OWA published through Microsoft Threat Management Gateway (TMG) server.
What was happened, after the login screen, we were being presented with a blank page. Looking at the code of that page, you saw that not a lot was being returned.
After some digging around (a lot of digging around), I found a page with some information on Update Rollup 2.
We decided to go a head and install Update Rollup 3. This can be found here. After installing this update, OWA now functioned, with a new problem. Images are not being displayed in OWA. All we get is a blank navigation menu.
After doing some research, the only fix I have found is by doing an reinstall of the CA role. This can be done by doing the following:
Setup.com /mode:uninstall /role:CA
Setup.com /mode:install /role:CA
My advice would be to stay away from the update rollups unless you need to install them. From what I can tell, they are causing more problems than they are fixing.