There has always been both a number limit, and a timeout limit. How large is the playlist? If memory serves, 500 is generally the number, but there’s also size considerations, if the metadata is larger than normal. And if you’re experiencing a little wifi interference , it’s possible that the load process is failing on a time out. 

Oh, wow...I was unaware, but it can’t be 500 songs, it just started happening with these playlists about 3 months ago and I’ve had 2200 songs in both of them all along.  Very interesting, indeed.  It’s not only happening with my system, but at my folks house as well.  Thanks for the reply!

Probably worth submitting a system diagnostic within 10 minutes of experiencing this problem, and calling Sonos Support to discuss it.

There may be information included in the diagnostic that will help Sonos pinpoint the issue and help you find a solution.

When you speak directly to the phone folks, they have tools at their disposal that will allow them to give you advice specific to your Sonos system and network.

I called Sonos support about this issue, the person I spoke to had no clue what the deal was...maybe I’ll call again and speak to someone else

Though the official line maybe the list can only be 500 max, I’ve read about people complaining they used to be able to play the Dutch top 2000 playlist and since a couple of months are no longer able to.

Could be a change on the Spotify side.

Amazon Music has set a 500 song queue limit in Sonos, but that limit doesn’t apply to Spotify.

As @Airgetlam said, the process is likely failing on a time out.

@106rallye - Interestingly, I tried to load that Top 2000 playlist and it worked when the Five was wireless. I’d moved speakers around so connected the Five back to Ethernet and couldn’t get the playlist to load. Disconnected Ethernet and the playlist added to the queue again.

There is a 10 second timeout for loading any playlist, as well as any size limits imposed by the service itself. If something has slowed down the network connection between the service and a particular speaker (the Coordinator in the group specifically), that could explain why a playlist that used to load ok suddenly does not.

Next time it fails, time it from start to error. If it is 10 seconds, that’s the problem.

All great recommendations, much appreciated!

Hi everyone, although I’ve had a number of Sonos speakers for years now, this is my first time posting in the Sonos Community. I’ve been searching around on here lately precisely because of this problem. My main “playlist” of liked songs on Spotify is somewhere around 1800 songs long now. I didn’t have problems putting this entire list in the Sonos queue for the first couple of years that I was a Spotify subscriber, but I have been consistently encountering the “Unable to add songs to the queue” error for the past couple of months. The problem seemed a bit gradual, in that I could get Sonos to load up the long list to the queue after a few tries, but now it won’t work at all.

I worked with Sonos support this past week via online chat, and then was told to call in. The first person I spoke with focused on the wifi channel selections automatically made by my Linksys Velop mesh system, and the second phone support person I spoke with simply forwarded the following email to me, detailing the various limitations for various music services. (Note: the size of Spotify playlists does seem to be limited, there is no mention of Apple Music however. Using Airplay and Spotify Direct Control are suggested as workarounds.)

In the end, though, I don’t really understand why I was able to regularly listen to my entire Spotify library for years, only to encounter problems at the end of this year.

Music Service Limitations

• Amazon Music
  • Only able to add a maximum of 500 tracks to the queue at once
  • Amazon Music Unlimited shows only up to 100 My Music Playlists in the Sonos controller
• Heart of Space
  • 12 hour session limit
• Pandora Radio
  • 4 hour maximum session length
    • Note that thumbs-down ratings and skips will reset the 4 hour counter, while thumbs-up will not.
  • As of Nov 2016, Sonos displays the most recent 94 user stations (alphabetically sorted). The user can continue adding up to 155 more stations, pushing the least-recently-used out of the list we display (which could be from anywhere in the alphabetically sorted list). This will probably change in Kendrick, when Pandora is slated to go SMAPI.
  • 6 skips per station per hour (Not lifted with Pandora One)
  • 12 skips max per day (Pandora One lifts the daily max)
    Note: via testing, Sonos does not have the 12 skip daily max.
  • Pandora Plus and Pandora Premium accounts are meant for individual, non-commercial use. The cost of an individual subscription only covers the costs of one stream of ad-free songs. You can play your account on any supported computer or device you own, however, only one person can listen at a time on your account.
  • A Pandora Premium subscription is required on Sonos when searching for artists, albums, and playlists, otherwise, only songs and stations will return results.
• Rdio
  • Maximum of 3 Sonos Rooms Playing separate concurrent streams
• Soundtrack Player
  • Maximum of 100 Playlists displaying in the Controller
• Rhapsody/Napster
  • Maximum of 3 Sonos Rooms Playing Separate Concurrent Streams
  • Can stream to either Sonos OR Computer/Phone
    (When one is started the other stops)
• SiriusXM
  • Maximum of 1 concurrent stream
  • 4 Hour Max Session Length
• Slacker
  • 6 skips per station per hour (no daily limit)
  • Paid subscription lifts the skip limit
• Soundcloud
  • 100 Tracks per container (e.g. Playlists)
• Spotify
  • Roughly 500 songs per playlist (can be lower)
  • Each account can only be played at a single IP address at any given time
  • Concurrent streams are allowed within the same household
• TuneIn (Internet Radio)
  • As of version 5.4 (Devo), Sonos does not support MPEG 2.5 audio formats (MP3s) that have sample rates of 12 kHz and below. Most of our partners stream above this rate, but there might be some stations on services that do not have alternate streams.
• YouTube Music
  • All containers for uploaded music have a limit of 999 items.

*You can bypass limitations with Airplay or even Direct Control from Spotify

Solid info, thanks very much!  It’s pretty crazy that I was able to listen to my favorite playlist (with around 2200 songs), up until about 3 months ago.  Oh, well!