Possible Causes

• Incorrect version of Internet Explorer; IE version 11 is the only supported version.
• Will happen when not running MS Office 32-bit, but can be caused when other system requirements are not met. Ensure all system requirements are met, including 32-bit Office.
• ActiveX Control IE settings are not correct. If the computer is managed through CIT's Managed Desktop service, push out the Group Policies provided by the Managed Desktop group. or If the computer is NOT managed through CIT's Managed Desktop service, manually set the IE Internet Options settings.
• Longview for Excel is not yet installed. 
• If all of the above causes have been checked and eliminated, in some rare cases, a Microsoft patch is needed.  Install msxml.msi from https://answers.microsoft.com/en-us/windows/forum/all/where-can-i-download-msxml-now-that-the-download/544d9268-8579-4127-8935-e9f48ac40f1f (When you click on the download link you will have several options. Choose "msxml.msi" file.)