SONOS - “. . . server cannot be found”

Just recently purchased Sonos. I’ve set up subsonic and all of my data displays perfect on the app. Problem is when I try to play a song, I get the following message:
“Unable to play ‘[song]’ - cannot connect to SUBSONIC because the server cannot be found.”
Any suggestions on a fix? Thanks in advance.
“Unable to play ‘[song]’ - cannot connect to SUBSONIC because the server cannot be found.”
Any suggestions on a fix? Thanks in advance.