I had this problem with my plugin and therefore created a clean audio plugin to check if the problem also happened. It actually does.
The procedure is the following:
- Create a clean new audio plugin using Introjucer
- Start AU Lab
- Create a new document (only "stereo in / stereo out")
- Add the effect on the track. Effects > yourcompany > pluginname
- Try changing the view to "Output 1" (upper left menu, see attachement)
- Then AU Lab quit unexpectedly
- I added the crash report as well
Most of the other plugins I tried are not crashing, I therefore deduces it is a problem related to JUCE