Now that we have some solutions, I'm still trying to figure out what caused the problem. I think we all agree that creating the playlist on an iPhone or iPad caused the problem, but there must be more to it, or surely more than just us would be complaining? I'm wondering if we all added songs that weren't actually on the device yet, that were stored in the cloud as part of the playlist? For me, I created the playlist and listened to it for over an hour, while on a wifi network, so it's still a curiousity.. my phone was nearby and not on a wifi network, and my MBA was asleep, and didn't wake up until I was on another wifi network.
So I've tried both this solution and the previous (longer version). I can't get the playlists off my iPad. They no longer show up on my computers, but they still show on my iPad. I have even wiped my iPad and restored from iCloud and restarted iTunes Match on the ipad but the playlists come back. Not sure what to do now. Any suggestions?
I was actually on a plane when i made my playlist (as such i was in Airplane Mode). I added 12 songs to the offending playlist that were ON my device and didnt realize it had gone duplication crazy until i got home from the airport. In my case i have a theory that while in Airplane Mode the Music app kept trying to create the iCloud version of the playlist and didnt act smart and realize there was no network connection and stop like it should.
It sounds like your case is different though, so it pretty much kills my theory. Maybe time is a factor here? Perhaps we all created our playlists at the same time and it was an actual iCloud problem?
So here's an interesting wrinkle. I made sure that my iTunes Match was working and set up the way I wanted on my MBP and my wife's MB. Then I erased my iPad and started it clean. (I have a backup in iCloud and on my computer). Having started it clean, I then enabled iTunes Match on the iPad and guess what happens? The duplicating list appears on the iPad. Moments later it now reappears on both computers. Now I REALLY don't get what's going on here.
Now I've deleted all but 50 copies of the playlist from my MBP, have restored my iPad, and am watching the copies get deleted via iTunes Match on my wife's MB. Once my iPad is restored I'll see what happens. Thanks for everyone's help so far!
I'm glad I'm not crazy, though it's a bummer this problem goes beyond my original post
I followed the approach of:
1. turning off iTunes Match
2. In iTunes on the Mac Mini, removed all devices from iTunes in the Cloud (under Manage Devices)
3. Running "automator" to remove blank playlists -- awesome suggestion, thanks!
That *seems* to have worked. Turning off iTunes Match on the Mac Mini removed the duplicates, but only temporarily-- once I re-enabled iTunes Match they were back. I killed them with the Automator.
On my iOS devices, turning off iTunes Match, then turning it back on after Step 3 above *seems* to have solved the problem.
As for the beginnings of the problem, I too created my playlist on my iPhone 4, adding songs from the "iCloud/iTunes Match." I was not using airplane mode.
Never mind. Minutes after posting the note above, the 2,000 copies of my empty playlist re-appeared on my iPhone 4 and iPad.
At least they're gone from the Mac Mini :-\
I've been trying to get a refund from the Apple Store and have pointed the person I'm emailing with to this page in hopes that they can help.
I would like to add to the number of people having this problem. I created a playlist on my iPod Touch in airplane mode and it duplicated like crazy on my iPod Touch. Then when I got home, I found thousands of blank playlists with the same name on my MacBook Pro (MBP).
I have used Automator to delete the blank playlists from my MBP. I have now turned back on iTunes Match on my iPod but the playlists do not seem to be repopulating. I also cannot make a new one. The app is also very sluggish.
I've been able to remove the iTunes duplicates through the Automator.
Removing my devices from the "managed devices" list in iTunes, turning off iTunes Match on my iPhone and Mac Mini, resetting up iTunes Match on the Mac Mini and iPhone resolved my problem on *those* devices.
However -- nothing I've done can force my iPad to see the "new" iTunes Match/iCloud data. The iPad now shows different playlists (including the 2,000 duplicate, empty ones) and different music. It is clearly looking at an old version of my iCloud data and no amount of turning on/off settings and devices makes any difference.
Tonight I'll be going through a complete erase/restore of the iPad. Maybe that'll help...
(This is what I sent to the iTunes support team as part of my ongoing conversation with them)
I spent last night restoring my iPad to its factory defaults and then restoring it from a backup. As a result my iPad no longer shows the 2000 empty playlists and appears to be in sync with my iCloud songs. So that problem is solved -- though there's still no clue as to root cause.
However, now the iPad will not reliably play back the music. For example, I chose the first song in my newly-created "Christmas Music" playlist (not a Smart list), which the iPad started playing for a few seconds before stopping, rapidly trying to play each of the next 5 songs, skipping one of them. Then the Music app crashed.
On restarting the app, none of the songs will play. I've tried the wireless network as well as the 3G network, both of which have very strong signals. Clicking the iCloud icon temporarily begins the download process, but then stops. All of the other internet services on my iPad are fine.
On my iPhone4, the behavior is similar: I can play some songs in the playlist, but the iPhone often decides to skip the song I chose and play the next one in the list. Songs that play on the iPad don't play on the iPhone and vice versa. And the Music app just keeps skipping down rapidly to the next track, without even trying to play the songs.
I've tried playing songs from the "Songs" tab in Music and the result is even worse: the iPad can play one or two songs, but when I click to another song, it begins to download the song, then skips to the next song in the list, then freezes. The behavior is the same on my iPhone4.
This is very, very frustrating. At this point I'm getting to the end of my rope troubleshooting a product that was clearly released before it was ready.