Mixbus is intended to work with third-party plugins, and we work very hard to follow the best practices for the various plugin formats; nevertheless we can't guarantee that every third-party add-on will work on your system.
There are many thousands of plugins available; and each comes in multiple formats, for different OS's, in 64bit and 32bit versions. Similarly, Mixbus comes in multiple versions, and your OS as well. And all of these (Plugins, Mixbus, and OS ) receive updates occasionally which change their operation. So unfortunately it is not possible to anticipate whether a plugin will work on "your" setup.
From our testing, we feel confident that Mixbus works on 90% or more of the available plugins, on any platform. However, "Murphy's law" states that your favorite plugin will be the one that doesn't work, today.