Are you sure that the VL license is valid? Are you part of the organization that owns them or is this one you bought as a single license (which is likely invalid)?
That's why you can't do it. Volume License Upgrades are for Pro to Pro (Win XP Pro to Win 10 Pro, Win Vista Pro to Win 10 Pro, Win 7 Pro to Win 10 Pro; Volume Licenses cannot be used to upgrade Home).
You need to buy a retail license to upgrade Home to Pro. Read your volume license agreement.
"You may NOT legally upgrade from Windows 10 Home to Windows 10 Pro using the volume licenses. The only organizations that may do this are academic and nonprofit. Commercial and government can only use volume license SKUs to upgrade from previous business class (Pro, enterprise, etc...) operating systems."
I would expect even in the education/non-profit environments the "upgrade" process won't work; you can only wipe and reload using the appropriate media.
This topic area includes legacy versions of Windows prior to Windows 2000: Windows 3/3.1, Windows 95 and Windows 98, plus any other Windows-related versions including Windows Mobile.
ASKER
How come I have been able to upgrade home editions before with my VL license?