error 2343 Windows 10 iCloud uninstall fails

Are you running or did you load Office 2016 as your most recent version of Office before trying to uninstall/upgrade iCloud? If so, you will need to downgrade Office, either by physical media or through Office 365 (there is a way through the alternate languages/versions link on your My Account portal on the Microsoft Office website). You may need to re-enable the Outlook interoperability with contacts, calendar, and tasks, then sign out of iCloud before uninstalling/upgrading iCloud becomes possible. Afterwards, of course, you will need to sign in again. As it is impossible to avoid error 2343 when Office 2016 is/was the most recently installed version of Office prior to uninstalling/upgrading iCloud, you will still need to go through this again or wait to upgrade Office until some future version of iCloud supports the latest version of Office and is your current version.