Something went wrong when you open a file by using an Office Web App or Office Online Server
Original KB number: 2761265
When you try to open a file by using an Office Web App or Office Online Server, you receive the following error message:
Sorry, something went wrong
An error has occurred on the server.
Troubleshoot issues with Microsoft SharePoint Foundation.
Correlation ID: <Correlation ID>
This issue occurs when you log on to the SharePoint Server by using a system account. Office Online requires the SharePoint server to pass a user token on every request. However, SharePoint Server cannot create a user token for a system account.
To work around this issue, don't use a system account when you log on to a SharePoint Server site.