Recently I had to reinstall my entire infrastructure, and one of the servers was the Office Web Apps server. Unfortunately the server was willing to do anything, the only thing I got was a white screen, or the ‘old’ WebReady Document view appeared. The discovery URL (https://webapps.exchangelabs.nl/hosting/discovery) was working fine, so at least something was working.

Another thing that was clearly visible was that processor utilization regularly peaked to 100%, sometimes staying at 100% for a longer period of time:

Clearly visible was that Office Web Apps was causing this:

The eventlog revealed more information, lots of EventID 1000 and EventID 1026, indicating something is broken on the application layer:

When checking the Office Web Apps farm itself a warning message “WARNING: It does not appear that this machine is part of an Office Web Apps Server farm.”

When using the Get-OfficeWebAppsMachine cmdlet the output turned red, indicating a more serious error:

Now this is what happened: I installed Windows 2012 R2, installed the prerequisite software and then installed and configured Office Web Apps. The next day I updated the server using Windows Update, and that turned out not to be such a good idea.

In the Plan Office Web Apps Server article on TechNet (the last section called “Planning updates for Office Web Apps server) it is stated that using an automatic updating process is not supported and that updates should be applied in a specific way as described in the Apply software updates to Office Web Apps server.

On a single server farm you have to remove the server from the Office Web Apps farm, update the server and create a new Office Web Apps farm.

In case of my ‘broken’ Office Web Apps server the approach is similar, except I didn’t have to install the updates, just remove the server and recreate a new Office Web Apps farm using the following commands:

Remove-OfficeWebAppsMachine
New-OfficeWebAppsFarm –InternalURL https://webapps.exchangelabs.nl –ExternalURL https://webapps.exchangelabs.nl –Certificate WebApps

After recreating the farm and rebooting the machine it was working as expected.