After upgrading to Tahoe and iOS 26, the sync function is not working for music

This worked for me!!! THANK YOU!

The Full Screen worked great. Thank you for that. This has bugged me for a few months now.

great suggestion. worked for me to synchronise my iPod 5th generation :-)

Yes! It worked. So random. I hope Apple is working to fix that with the new update.

I'm now just discovering this issue and I'm running 26.1

This is the workaround. Thanks, Brother Man.

Finally deduced that during the update to OS26 the music library file had become corrupted!! So binned the corrupted file and initiated a new music library file. After uploading from my hard drive 11,500 albums onto a new library file all seems well. However there are a few caveats in the new music app compared to the old one. 1) you cannot play music immediately, the app will crash. 2) You have to wait a while for all of the 'data' to load into the new music app before you can play any music without it crashing especially for a local library of this size (I haven't timed it but I leave it around half an hour from opening to be safe. However previously I could play music straight away, so this is a pain). 3) If syncing this to your iPhone, you need to be patient. when you click on the iPhone in the side bar of finder, it will appear blank for dome time. You need to leave it until all of the information is there, as in the sync button. Syncing new music will take as long as it takes dependent on the size of your local library.

Please be mindful that this only applies to a local library stored on an external drive. I do not use cloud based music, so no idea how that is behaving for other users.