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See Empty/corrupt iTunes library after upgrade/crash. If date added is important to you then reverting to an older uncorrupted version of your database, then trying to bring that up to date with the contents of the media folder, might be the way to get that information and your playlists as well.

tt2

I had the same problem. It appears that my iTunes Library.itl was corrupted. With the help of Apple support we created a new iTunes library and I moved all the songs there. Now the iCloud sync is in progress. Unfortunately, Date Added for all the iTunes content will be the date on which you rebuild the library. I also need to try and export my playlists from the old library and import them back to the new.

I don't know about the OP, but the recommendation here as far as rebuilding the library didn't work for me (though I appreciate the suggestion). Still waiting for an answer on this error. I have a call with Apple's iTunes team later this morning to see if they have any other suggestions.

I have a question though, is it happening after "Waiting to upload songs?" That seems to be where it gets stuck for me.

Did you try and build a completely new empty iTunes Library/Folder and populate it w/ a couple of songs and get them uploaded. That's how I tested it. Worked. Thereafter I copied all the tunes from the old library to the new one. That took some time and gave first all kinds of weird statuses on songs but it appears that it's all sorted out now and every new song will be uploaded/matched, too.