Installing Cubase 10 with Wrong Upgrade!

Hi All
I’m a newbie here so please forgive my ignorance.
I bought an upgrade licence for Cubase 10 Pro on special offer … yey!

however, I purchased the upgrade from Pro V8.5 which I have in a box (all good so far)
but …
The eLicencer says that the licence installed on it is for V 9 (which I don’t remember installing, but I must have at some point right ?)

Anyway …

When entering my NEW C10 Pro activation code i get the following message:
“Currently, there is lo licence available which can be upgraded by your upgrade licence.” etc etc

So … I REALLY scared of re-installing V8.5 out of the box in case it screws my eLicencer completely
but is this the only way to downgrade my installed version.
Or have I just wasted my upgrade fee?

this seems ridiculous that an upgrade from an older version is not compatible with newer versions!
I’m a software developer and I’d get my arse kicked if I did something like this to my loyal customers.

Thanks in advance

There is a chance your 8.5 license was within the “grace period” when activated, updating it to version 9. You will probably need to contact the seller to see if you can somehow exchange for the correct license code.

A similar thing happened to me.
I contacted Steinberg support and after they verified the purchase they issued a working key.