When opening a Excel file in ArcGIS Pro I get an error or the worksheets never load.
Solution
To resolve this error -
1. Go to the Windows Control Panel>Add or Remove Programs select the Microsoft Access Database Engine 2016 (if present) and click Repair.
If the issues persist, or this program is not installed -
1. Go to the Windows Control Panel>Add or Remove Programs and uninstall both Datamine Discover Add-In for ArcGIS Pro and the Microsoft Access Database Engine 2016 (if present).
2. Reinstall the Datamine Discover Add-In from its installer.
This will check and reinstall/repair the Access Database Engine.
More details in the ESRI Help here -