I have Volumio superstar, pi4 sw 2.907. When I connect my Hifime spdif to usb converter (my aim was to connect a chromecast audio this way) it will not show up as an input.
After restart I get an error message that metavolumio plugin can’t start. Also after restart, nothing can be played by Volumio, “failed to open alsa”. After disconnecting Hifime and a new restart Volumio is working again.
The reason I upgraded to superstar was to get this functionality but obviously Hifime is in some way not compatible with Volumio.
Someone has an idea?
For official dedicated support contact techsupport at volumio dot org 
I think your converter works the other way around, AKA USB to SPDIF
In any case, I suggest you to update to latest version. There is a fix for all the other symptoms you are reporting
It is a spdif to usb adapter, https://hifimediy.com/product/hifime-ur23-spdif-optical-to-usb-converter/
It works fine connect to a PC.
I have upgraded to latest sw version but the result is exactly the same as before. I guess something in the core sw must be added to accept this add-on.
Just on the off-chance, do you have ‘Digital & Analog Inputs’ selected in ‘Settings’/‘Sources’?
