@indigo it seems like you run into the same problems I have been encountering when using the apc mini with puredata (organelle platform). In my case the crash happened when I sent a lot of midi data in one go to the apc (to turn on/off the led buttons) to create a visual representation of my sequencer patch. The APC Mini is apparently not designed to be used for this and chokes up when it receives too much midi messages in one go. The only workaround I found was to limit the speed at which data gets sent to the APC.