Unable to process the request when opening an Excel document in SharePoint 2010

“Unable to process the request when opening an Excel document in SharePoint 2010”

 

Open the Document in the Client Browser

Navigate: Site Actions –> Site Settings
Click the Site Collections Features link located under the Site Collection Administration section of the page
Locate and active the Open Documents in Client Applications by Default

Open the document in the Browser

Perform an IISRESET and you will now be presented with the tried and true standard “Open Document” dialog