A funny thing happened while implementing Office Web Apps 2013 for my recently new SharePoint 2013 environment. Just to show you that no matter how much experience you have you can still do “stupid stuff”.
The setup went well and all seemed to be working fine for about a week. I had installed some WSUS updates on the Windows 2012 server hosting all of this and performed the requisite restart. A few days later I wnet to open a document in the browser and started getting all these errors. The pop-up display was not working and if I tried to view/edit in the browser I got “File not found” or “Try opening in Word” errors, not good.
After about an hour of plowing through ULS and event logs a light bulb went off. When I originally setup the VM I had violated a cardinal rule of server configuration. I had not assigned a static IP address to the server. This seemed to through a monkey wrench in the works. Even after assigning a static IP and ensuring that all of the vaious site host names were configured with the powershell command Get-OfficeWebAppsHost, which they were. Finally restarting the SharePoint server resolved the the problems.
Moral of the story, follow your check list no matter how many times you have done something. Even experts screw-up from time to time.