If your users are seeing a blank page when logging on to Outlook Web Access then it’s worth checking whether a recent Exchange update rollup package was installed.

The problem appears to be some missing files in one of the Themes folders used by OWA. There are two solutions that we found to work and your mileage may vary on each of them. We have however heard that these solutions also work on the same issued by rollups 2 and 7.

Option 1
Firstly, simply remove the rollup. You can find the roll up by going to the Control Panel then in to Programs and Features (Add/Remove if you are in Windows 2003) and viewing the installed updates. Find the very recent roll up and uninstall that.

Roll up 9

Option 2
If you want to keep the rollup installed then you could try this solution, which worked for us on our own server, however it’s worth checking on a test machine first.

Go to your OWA folder which is typically found at the location below. You can check the location by opening the IIS Admin tool and checking the location of the OWA virtual folder.

You will see a number of version folders, each starting 8.1.x and these contain the assets and images that make up the OWA web page. The most recent one (with the highest 8.1.x number) was most likely created by the recent rollup.

Version folders

In the screen shot above you will see that we have 8.1.359 and 8.1.393, with 8.1.393 being the most recent and 8.1.393 being the last working version.

Make a copy of the most recent folder and put it somewhere safe. Then copy the Themes folder from the last working version (in our case 8.1.359) and paste it in to the most recent version (in our case 8.1.393).

Finally, open up the Microsoft Exchange Management Shell from the Exchange programs group and enter the following command hit enter.

Once the command is complete OWA should be working, and you won’t even have to restart Exchange.

As I said your mileage with each solution may vary and as ever you will want to ensure you have backups of Exchange before attempting either option.