Volumio does not start… I bought a Pi3, put Volumio an SDcard (PC), put SDcard into Pi3, put LAN-cable into Pi3 (no other USBs, no HDMI, just power cable). The Pi3 does not boot. Then later TV screen via HDMI shows: “ERROR: netdev:wlan0 already exists”. What’s this? Other software (RuneAudio) works fine,
I think that I would try to reflash the SD card, after making sure that the checksum of your download matches that on the download page.