I tried entering Time Machine for the first time today since upgrading to El Capitan. It starts to show the TM screen and then quits. I cannot enter Time Machine. I find that one person reported this issue in the Apple Discussions a few days ago but he has not received a reply. My iMac is regularly doing TM backups - it's just I can't go back into them. This is, to say the least, not a happy situation. Any assistance would be most welcome.