Upgraded to El Capitan this morning without issue. No problems until my mac went to sleep. When trying to wake, it restarted around 7 times. Will work fine for most things now, including photoshop work. However any attempt to enter time machine or back up using time machine automatically shuts it down. Never had this issue until this mornings update. Any thoughts? I do like the new OS, and would love to not have to take it back to Yosemite. But I do need the system to be stable and to be able to back up. Thanks in advance.