VST3 GUI on Linux just a grey box about bass21

[jpcima]

What host is this? is the problem happening with all DAW software?

[dromer]

Sorry, this is using latest carla 2.3.0.
Now also tried with Ardour 6.8 and there it works.

[jpcima]

The same here, carla 2.3.0 as dev host.
It's a nothing-special juce based editor.
Might the logs tab report anything relevant perhaps?

[dromer]

Indeed, the moment I load the plugin I see: JUCE Assertion failure in juce_AudioPluginInstance.cpp:203

[jpcima]

From what I've collected, it's a bug of uncertain reproducibility, and it happens as result of a X11 BadWindow error.
I had reproducibility under Carla 2.3.1, but not under a git version of Carla.

Note that I had this problem occur, not only with this plugin, but with other plugins not based on Juce.
This bring me to suspicion that the source of this problem is possibly in Carla.