Ever since running Nuendo 15 I have had to add WaveShell1-VST3 to the Blocklist. This now takes a couple of minutes to launch Nuendo and, even more frustrating, it takes minutes to launch the Waves effects that are already installed on the tracks.
Because I received this message every time I launch Nuendo I have added it to Blocklist
Please tell me I am not the only person to have this issue and that there is an easy fix! 
…?
Make sure Waves Central is fully up to date and make sure the latest Waves Local Server is running.
Then reboot your system.
If it still fails, please provide more info. Your system and which version of Waves you are using etc.
Sorry to be picky but you didn’t mention rebooting or checking that the WavesLocalServer is running. (Check in task manager). I presume it is.
Also, you said waves 3.6.9? I’m not sure what that is but it looks like the shells you are using are version 16. Presume you have licenses activated etc.
And also worth a check:
Have you done a removal of older waves versions (in central) and cleared the central cache.
Why do I say all this? It is not guessing btw, I had this exact issue recently and one or all of the above fixed it. I can’t say exactly which one as I did them all simultaneously.
btw, if that message appears again - try just clicking wait for the plug-in to respond - see how long it takes.
Hi Phil,
I have tried all your suggestions as well as re-installing my Waves plugins and have exactly the same problem. Alas.
Waves claim that their plugins weren’t confirmed to work with Nuendo 15, and to contact Steinberg. Steinberg claim the problem is to do with Waves and to contact them for support. This is almost causing a feedback issue neither are willing to offer definitive answers. My fault for trying to keep my software up do date!
