In my case Cubase 14 would blacklist it permamently. It let me unblock it once, and then it blocked it again the next time I opened Cubase and this time it would say the unblocking failed, contact the plugin vendor. If it starts happening again in Cubase 15, I’ll report back.
I mentioned in another thread that Cubase 12 saw Scaler 3.2 as a 32bit plugin and put it in the blocklist. First time that has happened.
Same here, was already the case with Scaler 3.1.x and now with 3.2 as well. 
In this post Cubase 14 Pro puts Scaler 3.1.2 on a VST Blocklist - #12 by kjlietz I explained how you can get rid of the annoying block. It won’t take you even five minutes.
Thanks for the tip, will try tonight when I get home 
If you delete the folder “Cubase Pro VST3 Cache” it won’t stop Scaler 3 being blocklisted. But it allows you to unblock Scaler 3 at your own discretion. I had to unblock Scaler 3 once in Cubase 14 Pro and once in Cubase 15 Pro later. Since then no blocklisting anymore. But it might come back after the next service update.
Besten Dank
Will try again tonight.