I am no expert but I have a music library all hooked up. My actual music is about 5 folders down in my NAS drive but the route on my controller is only 2 folders down - and it finds all music files below that - so perhaps if you go \\mac-2019\mybookstudio it will work? 

And just in case...please ensure “imac-2019” is actually turned on and on the same network.

And this could help

https://support.sonos.com/s/article/2401?language=en

I would also perhaps take the dash (-) out of the device name (iMac-2019) too, because those type of netbios charachters can occasionally cause issues… just in case !! Oh and then change the shared path accordingly.

many thanks for the advice. I used \\imac-2019\mybookstudio and I'm getting the message ‘ THE COMPUTER IMAC-2019 REFUSED TO LET THE SONOS PRODUCT CONNECT TO IT’ 

I've switched on all the options I can find in ‘sharing’ but no joy.

It wouldn’t accept the iMac 2019 without the dash incidentally.

cheers

David

Don’t use spaces if that’s what you did? .. change it to “imac2019” ..sorry that’s entirely my fault for not clarifying that point. 

And (for clarity) after the rename has been done, then change the pathname to the same too.