I have a Sharepoint 2013 farm with Office Web Apps binded. Everything works fine internally but recently I published the Sharepoint Server and the Web Apps Server, so the farm is accessible from outside. The Web Apps Server is behind NAT (Port 443) and behind reverse proxy. Word, Excel and OneNote work without a hitch in this configuration but Powerpoint gives an error:

"Either you've lost network connectivity or our server is too busy to handle your request. Please check your network connection and try again later."

It seems to be able to load the application itself since if I click "New Document" and choose "Powerpoint Presentation", while it still gives me the same error, it loads the application with all menus grayed out. It also creates a Powerpoint Document and when I download it it's a perfectly fine blank Powerpoint document.

The reverse proxy doesn't even rename the URL, and it obviously works fine since all other applications work fine.

I find this problem rather interesting and I'm sure that someone with more knowledge on Office Web Apps will have some suggestions.

Any help will be greatly appreciated. 

Hi Georgi,

I recommend to run the command below to re-configure the binding for association between SharePoint and file name extensions:

Remove-SPWOPIBinding -All:$true

New-SPWOPIBinding -ServerName <WacServerName>

Set-SPWOPIZone -Zone "external-https"

If above cannot work, please check ULS log for more detailed error message for further research.

Thanks,

Victoria