Excel Data.ImportExcel operation Failed

[Kulkul]

Hi @Ben_Osborne

Have you update Revit 2020 to Revit 2020.2.3?

https://help.autodesk.com/view/RVT/2020/ENU/?guid=RevitReleaseNotes_2020updates_2020_2_3_html

Similar issue have been discussed here:

Data.ImportExcel operation failed. Excel is not installed

To @Alban_de_Chasteigner’s point, this is almost certainly a failure that stems from a bad installation, likely causing an issue in the registry related to interop. A repair should help, but you may need IT to clean the installation entirely and try again.