Got this error after configuring Office Web Apps for SharePoint.
Digging into the ULS for Office Web App [C:\ProgramData\Microsoft\OfficeWebApps\Data\Logs\ULS\***] and found the following error messages when browsing a document via OWA
HttpRequestAsync, (WOPICheckFile,WACSERVER) no response [WebExceptionStatus:ConnectFailure, url: xxxxxxx ...syncResult asyncResult, Exception& exception) WOPI CheckFile: Catch-All Failure [exception:Microsoft.Office.Web.Common.EnvironmentAdapters.UnexpectedErrorException: HttpRequest failed ---> Microsoft.Office.Web.Apps.Common.HttpRequestAsyncException: No Response in WebException ---> System.Net.WebException: Unable to connect to the remote server .... FileUnknownException while loading the app....
Checking Application Event Logs and got the following error
Exception type: ExcelWebRendererException Exception message: We couldn't find the file you wanted. at Microsoft.Office.Excel.WebUI.EwaState.OpenWorkbook() ...
Turned out that this is due to certain URL not being resolvable by Office Web App Servers.
Here is the catch, the SharePoint Web Application of mine is using multiple Zonez for authentication. The default zone was used for internal servers (not registered in DNS) while Intranet Zone was used for all users.
After the SPWOPI binding is done, the OWA takes in the Default Zone URL whenever user accessing office document via Intranet Zone. The Default Zone’s URL is never set in DNS and hence error thrown.
The workaround is to change the HOSTS file in OWA server (C:\Windows\System32\drivers\etc\hosts) to add in the IP of SharePoint Web Server with Default Zone’s URL.
Alternatively, if the Default URL is okay to be exposed to public. Please feel free to add in a DNS record.