Hi Thought i would put this out here, although currently the mac is running now it hit an odd glitch a few hours ago. MBPR Late 2013 - 128gb ssd When i got home and woke the mac from sleep the whole window had frozen, i had no option but to power it off. Upon restart the folder with a question mark flashed and would go no further. I then did the following: Booted up holding option key - went straight to internet recovery In recovery tried disk utility - NO HDD found just the recovery OSX BASE 1.2gb partition In Recovery tried Time Machine restore, found network disk but could not restore as could not see a hard drive on the mac In recovery tried fresh install - Again could not find a drive to install to. So while hanging on the phone to Apple support i tried booting into safe mode and the mac booted fine, everything working. I explained this on the phone and the lady was stumped, she verified with a colleague and agreed it needed to come in as they couldnt understand how this was possible. Anyways whilst on the phone we went back to recovery and again disks were not visible at all. Booted back into safe mode and all was fine. Anyways they think the SSD is knackered (unlikelyimho). after they booked appointment i wdecided to uninstall the last thin i instaled this morning which was Synology Assistant (for locating my nas on the network) and rebooted. It rebooted to normal mode ok this time. SO i thought i would try and select startup disk on reboot, and bam no disks again. After another reboot i got the question mark again but after a few minutes it went through. However now if i reboot it sees the startup disks ok again and reboots perfectly every time. Stumped is not the word!