Error: Couldn't reserve audio samples

[lbls55]

Hi Mike, I've installed your incredible Fruitbox v2 on a RPI 3b+ with a PiFi dac+ v2.0 on a fresh buster raspi Os. I have an issue that I can't solve: I've set the auto launch of fruitbox in /etc/rc.local as described by yourself, and fruitbox stops, saying "error: couldn't reserve audio sample". I hit enter and i come back to the buster desktop. When I launch fruitbox again using command line (cd /home/pi/fruitbox and ./fruitbox), it works like a charm...Any idea to solve that???