Steinberg AU wrapper issues with Logic Pro

I am using vstsdk3612_03_12_2018, and few customers reported us that plugins won’t run on their Logic Pro. They gets verified with PASS result, but are not shown on the plugins list.
It’s strange issue because it works on most Logics but not all.
MacOS is Catalina/Big Sur


auval -strict says

    • PASS


I suppose it was my bug within stereo/mono bus configuration. Default is Stereo arrangement and I deleted SupportedNumChannels 1 channel configuration and it works with Logic. However Logic should report this and/or in Validator.

We managed to solve the problem on 99% Logics Pro, however we have still few user’s Macs where our AU plugin is not shown in the Instruments list. It is correctly detected & validated in Plugin Manager. SDK is 3.6.12. How to debug the problem with Logics? Steinberg please help.

It worked after creation of new account with admin privileges. Seems to be Apple bug.

This seems to be related to an issue of Apple or Logic where the is corrupted and need to be deleted.

Try to delete this file


And maybe this second file (not 100% sure) too


Hello Yvan
This helps but not always. On some Macs I need to create a new user account to force the plugins to work.

You should report this issue to Apple. This is not a bug of our Wrapper at least this is our understanding of the issue,

Hello Arne
We contacted Apple and they said that “this is not Logic failure” :(.
They said this may have different causes including user permissions etc.
Do you (Steinberg) have the same problem with your plugins that they are not recognized on the Instrument list in Logic but they are “successfully validated” and nothing helps?
Sometimes clearing the cache helps but not on every computer. Clearing cache is not problem for the users, but sometimes nothing helps except creating the new account. This is most important issue for us.
If you cannot talk about this on the public forum I can talk to you by company e-mail address.

Someone wrote about this issue here: Padshop 2 not working in Logic - #7 by Gerrit_Junge
Any solution?

Funny. Did Apple tell you why Logic does not see the plug-ins while all other AU hosts see them?
We have not heard back from Apple regarding this issue and as this issue happens to other developers too who are not using the wrapper included in the SDK we see Apple in the liability to fix it, or at least give feedback what the problem is.