I have an album purchased today from iTunes. It is present in the music library and the folder contains the m4a file for each track. iTunes info shows complete meta-data to be present for the album. After indexing the music library, the album does not appear. I have searched composer, artist, album, and song indices and cannot find it. I've done the re-indexing several times. Going to the music library with the browser shows everything in order. As far as I can tell, the index is otherwise intact, but I have a large library and cannot be certain of this.
Best answer by BillF
A further update. I reported the indexing issue via twitter. Since overnight indexing seems to be complete, I've agreed to treat it as "solved", though I'm not entirely happy. I did report that the failed indexing consistently results in a "completed successfully" message even though it did not. It produces exactly the same message as the overnight processing.
After some experimentation, I am pretty sure that the "scheduled" index is different from ones initiated on command. I added a new album, did an index, and verified it was incomplete. I repeated the index several times -- all produced incomplete results. I then changed the schedule to index a few minutes in the future and went back to doing other things. (Sonos was playing music throughout all of this.) After a half hour or so, checked notifications and was told indexing had happened. Checked library, and index seems to be complete.