It could be that the FritzBox does not support SMB v2, or you can try the path with the IP of the router instead:
//fritz.box/JeroenMusic
or this
//192.168.x.x/JeroenMusic
Do not put your music directly in the root of the usb drive but in a subfolder, for example "music".
On the FritzBox
Go to "Home Network", "USB/Storage"
On the "Device Overview" tab:
- check "Storage (NAS) function enabled".
On the "Home Network Sharing" tab:
- Check "Access via network drive (SMB)" and give the share a name, for example "USB"
Do NOT enable "Support for SMBv1"
Go to "System" > "FRITZ!Box Users"
- Create a user with password
- Check "Access to NAS contents"
- Click "Individual settings"
- Now Configure Access Rights to the subfolder of your Usb drive
In Sonos, use the path:
//<ip-address>/<sharename>/<usb-volumename>/<subfolder>
In your case:
//192.168.178.1/USB/JeroenMusic/music
You may use both forward slash and backslash. It's what you prefer.
Thanks all for these positive responses. Made my day!
I am going to try all of it and give feedback soon .
( due to travelling that will be in three weeks time, but this big help needs some feedback)