PowerPoint Web Application encountered an error: Service unavailable. Please try again later.

That’s funny, but PowerPoint stop working today without any visible reasons. Error message about service anavailable

I tryed to get into PowerPoint Service Application, but System.Collections.Generic.KeyNotFoundException: The given key was not present in the dictionary.

and this in log:

1: “Could not find default ServiceProxy or it does not implement IWacServiceApplicationProxy”

2: “Unhandled exception caught when executing web method handler: System.NullReferenceException”

First of all – re-create PowerPoint Service Application. Problem with given key is gone.

Investigation… Something wrong with the PowerPoint application proxy. This solution using UI did’t work for me and  . It was not hooked up to the default proxy group, but admin pages said different. (Thanks to Dale Hirt)

Get-SPPowerPointServiceApplicationProxy | Remove-SPPowerPointServiceApplicationProxy -confirm

Add new one w-AddToDefaultGroup switch:

Get-SPPowerPointServiceApplication | New-SPPowerPointServiceApplicationProxy -Name “PowerPoint Proxy” -AddToDefaultGroup

Verification:

$(Get-SPPowerPointServiceApplication).ServiceApplicationProxyGroup.DefaultProxies