SharePoint 2010 - Excel Web App error "An error has occurred. Please try again."

Question

On one of SharePoint sites on our server. While opening few .xlsx files users(including me) are getting the error "An error has occurred. Please try again.".

When the user click's on any of these specific files, blank Excel Web App interface opens up with the following error.

In the same document library there are .xlsx files which are opening properly in the Excel Web App interface.

If i download these specific .xlsx files and open them in MS Excel they are opening normally.(I did this just to make sure the files are not corrupt somehow)

I have few pointers,

1) It is not user-specific, as its happening to multiple users for same file.

2) It is not File specific, as the file which is giving error, works fine on another environment.

3) It is not Environment specific, as other files in same environment are opening properly.

4) I had made sure that Excel Calculation Services and Microsoft SharePoint Foundation Web Application are working(started state).

Answer 1

We faced a similar issue with random Excel documents working for one, but not for an other person having the same hardware and software installed.

We had to install May 2015 CU for Office Web Apps in order to get rid of the issue. If you got a test environment I would give it a try. Here is the link for the CU. Please keep in mind the basic rules on how to update Office Web Apps server:

1. Get-OfficeWebAppsFarm and write down/save your settings
2. Remove-OfficeWebAppsMachine
3. Install CU on server
4. Recreate Web App Farm using your settings

Answer 2

I faced this in 2010 while accessing excel 2007 . Possibly:

The SharePoint 2010 Excel Services Application has not started properly.

The Security Token Service Application is not started properly.

The Excel Service account does not have permissions for the SharePoint content database.