SharePoint 2013 Excel Services Error–“The workbook cannot be opened”

Reminder that if you get this error while trying to open up an Excel File in a browser using Excel Services in SharePoint 2013.  Ensure the following:

1. Ensure your site/library is set as a “Trusted File Location” in Excel Service Application settings (Central Admin –> Manage Service Apps –> Excel Service App –> Trusted File Locations)

2. Ensure that your Excel Services process identity has been granted access, you can do this via PowerShell:

$webApp = Get-SPWebApplication "http://intranet.ad2012.loc"
$webApp.GrantAccessToProcessIdentity("ad2012sp_services")