Unable to CAST COM object. Repair Tool for Microsoft Office Interop encountered using Office 2013

Hi, we encountered this error even after Repair Tool have been run. She upgraded to Office 365 and reverted back to Office 2013. Repair tool have been run, error is still encountered. Is there something that I am missing in configuration?

Unable to cast COM object of type ‘Microsoft.Officeinterop.Excel.ApplicationClass’ to interface type ‘Microsoft.Officeinterop.Excel._Application’.

Thanks!