Lync 2013 WAC Issue "Sorry, PowerPoint Web App Ran into a problem opening this presentation."

Issue: When users are trying to share PowerPoints in meetings the PowerPoint's are uploaded fine (mainly PPT) but the user receives an error "Sorry, PowerPoint Web App ran into a problem opening this presentation. To view this presentation please open it in Microsoft PowerPoint."

























































Environment:
(2) WAC servers behind a F5 Load Balancer
TMG Cluster with 4 TMG servers.
(7) Lync 2013 Enterprise Server


Trials:
I have tried a number of things to resolve this issue:
• Bypass TMG by trying internal - Fail
• Bypass F5 using host files and targeting each WAC server to ensure it wasn't an issue with one - Fail
• Tried loading PPT on other environments to ensure it wasn't a corrupt file - Success
• Loaded PPT on the WAC farm in our DR site - Success
• WAC SP1 - Fail
• Rebuilt both WAC servers - Fail


What I have used to troubleshoot this issue:
• Fiddler is the most detailed in helping pin point issues – Fiddler Showed the 200 during the upload but then the 500 during the failed download
• IIS Logs - had shown me pretty much what fiddler showed
• ULS Logs - wasn't finding much other than the 500 error until verbose logging was enabled then showed the following error relating to cache:


DiskCacheReader: TimeoutException [Machine: http://lyncWACServer01:809/diskcache/DiskCache.svc, Exception:System.TimeoutException: The HTTP request to 'http://lyncWACServer01:809/diskcache/DiskCache.svc' has exceeded the allotted timeout of 00:00:02. The time allotted to this operation may have been a portion of a longer timeout. ---> System.Net.WebException: The request was aborted: The request was canceled.   
DocumentInfoCache.GetDocumentCacheItem: Item found, 0 minutes old
SetCompleted - Completed with unthrown exception Microsoft.Office.Server.Powerpoint.Pipe.Interface.PipeApplicationException: Exception of type 'Microsoft.Office.Server.Powerpoint.Pipe.Interface.PipeApplicationException' was thrown.   


• Event Viewer on WAC server - fund this kind of useless        


Resolution:
In working on this a few commands came in handy:


• Set-OfficeWebAppFarm -openfromurlenabled - This command allows you to generate a PowerPoint right on the server itself. This is very useful in eliminating Lync from the equation as well as any network related issues. To get to this tool you simply browse straight to the server itself (or VIP.









How I did this was simply created a shared folder on the desktop, placed the path to the folder along with the powerpoint file (\\testserver\c$\user\test\PPT\Test.pptx in the first line and used the "Create Link". Then using the Test This Link I was able to see if the PowerPoint would render on the screen.


In my case no such luck, same old error as above. Since I Knew I was failing locally I figured why not turn up some more logging to see if I could find something. The command allowed me to do this:


• "Set-Officewebappsfarm -logverbosity verbose" this turned logging on high in OWAS, this also requires a services restart to complete.


With verbose to high I ran back through the same tests with the same result and not seeing much other than cache issues. Speaking with MSFT PSS we were informed that whenever a PowerPoint fails it's never cleaned from the cache and will no longer display. The only way to clean this is to remove the cache. To do this its back to stopping services on the servers browsing to "C:\ProgramData\Microsoft\OfficeWebApps\Working\d" and removing ALL of the contents from the "d" folder.













































































With the "d" folder clear, restart your services and give another test. In my case I was now able to render the PowerPoint file just fine. With everything back to normal so you can now disable the logging:


• "Set-Officewebappsfarm -logverbosity """