Carla-RackFX-VST crashes with Calf plugins

[PatS]

When I use Carla-Rack-VST to host an LV2-plugin, it works just fine with any LV2 except with Calf.
As soon as I open the GUI of any Calf plugin it crashes the DAW. Happens in both Ardour and Reaper.

I've gathered from other posts that Calf plugs are problematic in this regard. But I remember that this didn't happen with earlier versions (of Carla-VST?).

summary:
Reaper >> Carla-RackFX-VST >> any Calf plugin: crashes
Reaper >> Carla-RackFX-VST >> any other LV2: works
Ardour >> Carla-RackFX-VST >> any Calf plugin: crashes
Ardour >> Carla-RackFX-VST >> any other LV2: works

Carla-standalone >> Carla-RackFX-VST >> any LV2 including Calf: works
(this on the other hand suggests that it's not an issue of Carla-VST)

[sysrqer]

Probably related to this if you're running an up to date carla - http://kxstudio.linuxaudio.org/News/?ac ... c3-is-here

[PatS]

Ah, OK...I don't understand every detail, but is there a difference between Carla (standalone) and Carla-Rack-VST (as plugin)?

The issue I have is with Carla-Rack-VST (in Reaper and Ardour) whereas Carla (standalone) works fine.

Then again:

Calf plugin UIs will be missing their graphs by default, unless you disable running plugin UIs in bridge mode in Carla settings

This behavior (missing graphs in Calf plugins) I get when using Carla-Rack-VST in Qtractor:
Qtractor >> Carla-Rack-VST >> Calf EQ 5 band: no crash, but missing graph in UI

In other words - Why are there no crashes (with Carla-Rack-VST hosting Calf) in Qtractor and in Carla-standalone? Only Reaper and Ardour crash.

Hope I'm not confusing things