Hi @Martijn2308, Thank you for reaching out and welcome to the community. Sorry to hear that you have this error message on your Sonos system. This usually happens when The Sonos Controller displays "Unable to add tracks to the queue" or the errors listed when attempting to begin playback. This is usually caused by network communication problems, either between Sonos and your router or between Sonos and the internet.

• "Unable to add tracks to the queue."
• Error 1001
• Error 701

For this issue, I’ll ask you to do this troubleshooting steps:

Step 1 - Reboot the router

1. Unplug the router from power for ten seconds and then plug it back in. The router may take several minutes to come back online. When your network is back, try playing music on Sonos.
    

Step 2 - Reboot Sonos

1. All products (except Move)
   1. Unplug the power cord.
   2. Wait 10 seconds.
   3. Reconnect the power cord and allow one minute for the product to boot up.

Step 3 - Clear up any wireless interference

1. ​Change the SonosNet channel​

2. Move away common sources of wireless interference.

• 2.4 GHz or DECT cordless phones
• Wireless video transmitters that operate in the 2.4GHz or 5GHz WiFi band.
• Microwave ovens (May cause interference to nearby Sonos products when in use.)
• Wireless security cameras
• Wireless extenders and Access Points
• Wireless audio systems that operate in 2.4GHz or 5GHz band
• 2.4GHz baby monitors
• Wireless cable and set-top boxes
• Proximity to any other wireless device. (e.g., garage door openers, wireless picture frames, keyboard, and mice, etc.)
•  Known 3rd-party hardware interference sources.

Let us know what you have in mind with the advice above.

The Sonos community is always here to help.