I moved my music library to a new external hard drive, and it no longer works.

Don’t know Windows well but can you compare the sharing settings between the old library location and the new one?

Is the new drive going into sleep mode and failing to start fast enough to make Sonos happy?

I went with a NAS device to get away from having to have my desktop always on and dealing with it being tied up doing other stuff and unable to serve my music.

I don’t love having to spend time on the phone with a stranger just to get my system working, but if that’s what I gotta do to get the speaker system that I invested significant money into working, then ok.

Are there any error messages?

Are there any odd characters in your folder or file names? If so, they could be flustering the NAS. I avoid spaces.

How many tracks are in your library? I’ve seen users who get into trouble at a few hundred tracks, a few thousand tracks, while others can deal with the full 65,000 track library. The individual file path length might be an issue. Indexing is done by a player, not the PC. Long path lengths tie up more memory and run slower. It’s possible that there has been a timeout or out of memory error.

In your PC controller go to Help → Error Log…. There may be a message here if you started the indexing process from the PC.

A strategy that has been successful for some is to break the library into separate folders. Rather than \\NAS\music, use \\NAS\music\classical, \\NAS\music\jazz, etc. Up to 16 segments can be defined. The advantage of smaller segments is that each will require less memory and execution time. As far as the user is concerned, only the library Folders view will be impacted.