Hi, hoping someone can help! Thank in advance for any help. So I'd installed the High Sierra public beta on my Fusion Drive hard drive, and converted the drive to APFS. On the release of the GM, I tried to follow Apple's support instructions here: https://beta.apple.com/sp/betaprogram/apfsfusion , but on booting up from the installer disk I'd created, my Mac refused to recognise any peripherals (bluetooth mouse, USB mouse), so I was unable to get past the screen with the image showing me to turn a bluetooth mouse on. Using Option+Command+Shift+R I booted into recovery mode, reformatted both parts of the Fusion Drive back to Mac OS Extended (Journaled) then again using Option+Command+Shift+R reinstalled Sierra. So my Mac was then back on Sierra, and seemed to be running ok. I reregistered the machine for the High Sierra beta, downloaded the High Sierra Beta GM Candidate, and tried running it to get my machine back on High Sierra so I could restore from a Time Machine backup (unfortunately I only have High Sierra backups). On restarting, I got the Prohibitory symbol icon as shown here before the Mac booted up in Recovery mode. I powered the Mac down, restarted it, and Sierra booted up. I then created a clean Install MacOSHigh Sierra Beta bootable install drive, set that as my startup disc, and restarted the machine holding down the option key. Selected the Install Mac OS High Sierra Beta drive as my startup disk, and again got the prohibitory symbol before Sierra booted up again. Can anyone help please? Feel I'm stuck going round in a loop and not quite sure what the problem is. I'm keen just to restore all my files from my Time Machine backup. Thanks!