We don't know what happened, but something went wrong. Could you please try that again?

After building a new 2013 environment there was still a couple pieces missing in order for our end users to start using Excel Services. Unfortunately the environment started being used in a less than complete state and therefore things started to be reported before completing QA -- but why not have our end users be QA and live on the wild side?

In a way it was a blessing in disguise because it has now forced that I follow a step by step process in getting it up and working and am now sharing this with the community -- yeehaw!

Firstly, a report came in from a user who added an Excel Web Access web part that pointed to a regular ol' Excel doc they had uploaded to a library on their site. Once pointing the web part to the following error showed up...

Excel Service: We don't know what happened, but something went wrong. Could you please try that again?

Looking at Event Viewer on the front end server I saw the following...

No Excel Calculation Services is available in the farm

Duh! Excel Services hadn't been started so I started it!

After starting the service I still got an error...

Couldn't Open the Workbook: This workbook cannot be opened because it is not stored in a trusted location.

To create a trusted location, contact your system administrator.

Based on this I looked at what I had in Trusted File Locations and found that I only had http:// so I had to add https:// as a trusted location on the Excel Services Application

• Central Administration > Application Management > Manage service applications > click on your Excel Services Application to open it > Trusted File Locations
• Add Trusted File Location > enter https:// in the Address field
• Check the Children trusted checkbox and OK (I had no need at the moment to modify any other setting but you may)

Ultimately I ended up with what you see below...

However, after refreshing my browser I saw...

Couldn't Open the Workbook: The workbook cannot be opened

I had seen this error before so I wasn't completely bummed seeing yet ANOTHER error. And luckily it was the same issue -- in essence this comes up when the service account running Excel Services does not have proper permissions to the content database where the content resides.

I followed the following steps to resolve it...

Run the following cmd in SharePoint Shell...

• $w = Get-SPWebApplication –Identity <URL of the Web application>
  $w.GrantAccessToProcessIdentity("<service account>")

Finally, after this last step I tasted victory!