@Lunabear or others going from really old to newer versions on win7 or higher platforms.
I think that can happen going from ndis5 version of tap driver older(9.9.x.x) to ndis6 newer(9.21.x.x)
https://github.com/OpenVPN/tap-windows6/issues/17
The work around is apparently to remove the tap driver before upgrading (unless you want to manually add registry entries).
@5YmkoLQZ's advice should work, uninstall both, (optionally reboot), Attempt new install of 2.15.2 (run it as 'administrator'\with elevated privileges, tap install should complete.
If not and you run into something screwy where the old one doesn't uninstall properly, or you want to manually install new one,
or wipe all traces, or want to roll back to 9.9.x tap after the Eddie upgrade,here are two links that have helped me over the years:
https://community.openvpn.net/openvpn/wiki/ManagingWindowsTAPDrivers
https://openvpn.net/index.php/open-source/downloads.html [bottom of page is tap driver downloads and warns about the 9.9.x to 9.21.x issue]