I still have the same problem. Can’t install any plugin. Is there a rescue or, as usual, the answer in the case of volumio is to re-flash sd cards? I am fed up with this, the software is so stable that I have to upload the sd once a week. Every time after a few days it fills up to 100 percent and won’t let you install anything and spotify connect stops working!
Volumio Version:2.906
Hardware: Rpi3b
DAC:X6 usb