I had a similar issue when upgrading some slate plugins the last week or so. I have the subscription and it seemed to get screwed up when cubase scanned the new dlls. Got it to work…But Not sure what worked in the end, but I updated ilok software to latest, refreshed subscriptions in the ilok manager, then deleted the cubase blacklist files in C9 and C10. Restarted cubase 9 first and all was good. Even when starting C10 after all was good. Again not sure what step or steps fixed it.