Issue when persisting plugin states in Cubasis

Hi LSlowak,

I am an audio dev currently working on adding AUv3 support to one of our apps. While conducting tests in Cubasis 3, we encountered a compatibility issue when persisting plugin states inside the DAW. I’m reaching out in the hope that the Cubasis team can provide some insights on how to best handle this issue.

In Cubasis, when a plugin’s user interface is closed, the DAW is programmed to request a snapshot of the plugin’s state to be stored in its undo stack. This is fine for simple plugins with a few parameters, but it becomes problematic if the plugin states contain any user-supplied audio assets. A state object with a few megabytes of audio assets can quickly add up inside the DAW’s undo stack if the user toggles the plugin’s UI in quick succession. This can lead to Cubasis becoming unresponsive and eventually resulting in damaged projects.

From reading posts on the forum, it seems Koala is also facing similar problems when running in Cubasis. See posts: [My Cubasis project is “damaged”] and [Using large samples in Koala AUv3 makes Cubasis Unresponsive]

If possible, could the Cubasis team shine some light on how to best navigate this issue? Is there a way for plugins to opt out of Cubasis’s undo behavior? Cubasis is one of our favorite DAWs and we want to make sure our plugin works flawlessly inside it.

Thanks in advance!