Interesting, I can only seem to re-produce something similar (for me the plugin editor also has to be open) when debugging with Xcode. Also, it seem that this bug also makes Xcode hang (I need to force quit xcode). Could this be a weird situation with Ableton and the Xcode debugger? Were you able to reproduce this when you are not debugging?
It certainly happens every time here, also without Xcode running, and without the plugin editor open. Tested on two different Macs.
Further experiments - when i flip step 4 & 5 in the process to this:
1-3. same as above.
4. Now send some audio to the “B track”, by enabling “in” on track 3 and move up the “send B” slider on track 3.
5. On track 1, set “MIDI From” to the B track where JuceDemoPlugin sits.
6 .Live Crash, but sometimes it first start to paint random black boxes or colours in the Live UI!
Something must be writing in the wrong memory. Perhaps due to how the Juce Demo Plugin agree on shared data/channels/buses? Seems related to the midi output of the Juce Demo Plugin.
I’m using the Live 9.7.1 in demo mode (disabled save/load) if that could make a difference.
Yes I agree this seems to be related to MIDI not audio. I sometimes get a crash in ::memmove and I can see that the memory accessed has midi data in it. However, I can’t analyse further as Xcode just hangs completely…
I also cant see anyting from the audio thread in XCode when debugging through Live.
It was certainly not the problem with earler Juce versions. So, im guessing it has to do with the latest multibus refractorings somehow. One option is to go back in git history and see where it breaks.
And, maybe you can forward the issue to Ableton? (i’m thinking you have a better hotline than us small devs). They can easier debug it.
Its kind of serious - it prevents us to release plugin updates.