Issue with VST3 Plug-ins Not Loading Cross-Platform in M4L Wrappers (Mac & Windows)

Hi all,

First off—huge thanks to Elphnt for the amazing Max for Live wrapper tutorial! It’s been incredibly helpful as I’ve been building custom wrappers for my VST3 plugins.

That said, I’ve hit a snag when trying to make these wrappers portable between my Mac and Windows machines. Specifically, I’m loading a plugin using [plug_vst3 <plugin-name>], and everything works perfectly on the system where I created the patch. But when I open the same Max for Live device on the other platform, the plugin doesn’t load.

Here’s what I’ve observed:

• The plugin shows up in Max’s Plugin Browser on both systems.

• If I manually click on the [plug_vst3] object in Max, it loads the plugin correctly—even on the other system.

• However, if I don’t do that, the plugin fails silently.

• Once I save the patch on one platform, it stops working on the other again—even with the same plugin installed in the default location.

I tried debugging by comparing my wrapper to Elphnt’s SoundToys wrapper, which interestingly works cross-platform without any issues. I copied the initialization setup from that wrapper but it didn’t solve the problem in my case.

To further rule out plugin-specific issues, I tested with the free “Wider” plugin (thats the same one he made the tutorial with), installed to standard paths on both Mac and Windows—and I still see the same issue.

It seems like the plugin reference or path embedded in [plug_vst3] doesn’t remain valid when switching operating systems, unless re-initialized manually by clicking on the object. I’m guessing the issue may be related to platform-specific file paths or internal plugin IDs that don’t map properly between systems.

Has anyone else dealt with this? Is there a best practice for making sure VST3 plug-ins inside Max wrappers remain valid and loadable across platforms?

Thanks in advance!