Hi @jonblauch, thanks for reaching out and for sending a diagnostic report of your Sonos system. As I check the report. It shows that there are 5700+ tracks in your music library. I want to ask further questions to check on this issue. 

• How many total songs do you have in your Music library?
• Did you change PC/Mac or laptop before this issue happened?
• Are you trying to update it on a Mac or windows controller?
• Are there any changes made in the music path folder for your songs before this issue happened?
• Kindly check this article about Updating your Sonos music library for reference and some troubleshooting steps.

Let me know your thoughts on the advice above.

The Sonos community is always here to help.

1. There are about 9k files in my music library. THere does not seem to be any logic to what is missing. Some entire albums, and some .flac files ( concert downloads)
2. No changes to my PC or underlying library.  I moved my library to OneDrive ( Yes,  I have a windows PC), and then realized it needed to be on my PC, so moved them back. That is when I removed and reinstalled my music library
3. I have checked that article and see nothing there i have not tried

Did you look at the diagnostics I submitted>

Hi @jonblauch, thanks for the update and for trying some of the troubleshooting steps for this issue. I checked the diagnostic information that you’ve sent. But I can’t see anything wrong with it. So we’ll take this to the next step. I'll ask you to kindly contact our phone support team for further assistance and more in-depth troubleshooting steps. They may request remote access or screen share with your PC to check some settings and check what could be causing this issue. 

If you have other questions about your Sonos products, feel free to reach out.

The Sonos community is always here to help.