This item was not added to your Cloud Music Library because an error occurred.

Hello jillonius,

Based on what you've shared it sounds like you're experiencing issues with custom downloaded music. The file type you're using may be able to play on your Mac but be incompatible with Sync Library: Use Sync Library to access your music library across your devices - Apple Support

You can review your available options in the article above. Please also note the following.

Apple Music isn't a backup service. Make sure to back up your music library before you make any changes.

Regards.

I have had to

1. delete the pre-order files that are automatically downloaded (one copy says matched or error and the other says waiting)
2. Go to Accounts>Purchased and click on the "Not in my Library" tab.
3. Click on the Purchased download icon to re-download the file. The song then shows properly as Purchased in my library.

I'm having this same issue. It has to do with an iTunes pre-order (purchase -- not Apple Music). Pre-orders are always funky for me and I will probably stop doing them altogether because it often results in duplicate files. I had pre-ordered Neil Young's Chrome Dreams, which came with two early downloads.

Yesterday, when the whole album became available, I clicked on "check for available downloads" in the drop down menu only to find all the files were duplicated in my iTunes library. Half said "Waiting," and half said "Error." All of the waiting ones were titled with a "1" so I assumed those were the duplicates and deleted all of those (plus deleted from my computer).

I do see all of the other files in my iTunes folder and they seem to play fine. However, with the exception of the two early downloads (one says "matched" and the other says "purchased"), they all say Error under Cloud Status with grayed out downward arrows. When I click on an arrow, I get the dialog box with "This item was not added to your Cloud Music Library because an error occurred."

Not sure what to do at this point. I guess I could delete them all and then re-download but iTunes has become a wonky piece of software that has failed me over and over again in the past. At one point, I had meticulously changed all metadata and images to be more accurate. Then when changed computers, it all got messed up. Years of work lost. So I just don't even try anymore. Thanks for any help.

I decided to delete all the ones that say "Error." Then I retrieved them from the trash, put them back in the Neil Young Chrome Dreams album folder and dragged them back into iTunes. After initially showing as "Waiting" under Cloud Status, they now all say Matched. So case closed I guess.