Converted to APFS Now Cannot Boot ! Help Please

COmpleted a restore from time machine then went back to Utilities and converted again. A little different experience this time but ultimately same thing, converted to APFS without issue, this time showed bootable but when restarting didn't boot. Shows up in Disk Utility but doesnt show up on boot list (holding down Option on startup), not sure whats going on here. This volume is an SSD for reference. Only thing I'm thinking now is to force a clean install a restore/migrate after.

FInal update for the night, even fresh install will not boot after the initial APFS disk setup. Basically starts the install, reboots and boots into my other partition. Do a Startup Command and don't see the install. Looks to be all APFS related issues to me. For now restoring back to MacOS Extended and leaving it there. Will file bug tomorrow

I am in a similar position at the moment.

Updating to the latest beta failed for me - installation progress never went passed around 90% despite leaving for significant time and rebooting ended up in the same position. I attempted a time machine restore and 26hours later the restore was complete, just at the point where it was about to reboot it failed to make the drive bootable with the following error visible in the restore log:

OSInstaller[651]: [RESTORE] unable to boot from restored disk. Error: Error Domain=com.apple.DiskManagement Code=-69583 “Running bless to place boot files failed.” UserInfo={NSLocalizedDescription=Running bless to place boot files failed.}

On rebooting I end up at the non entry screen. When I launch recovery mode and access Disk Utility I can see the volumes and portitions correctly and the appear to be correctly populated with Data, however I am no longer able to carry out FirstAid on the volumes - the process fails. I am able to erase the Macintosh HD volume and recreate as APFS, however the same end result of failing to bless my drive occurrs after trying to restore or even reinstall the operating system.

I Am also unable to erase anything above the volume. Apples own support pages instruct that for a Fusion drive you should delete the container above the volume, not just the volume itself - however I cannot do this either. Internet recover fails right off the bat, telling me that I have to use the internal recover partition - presumeably due to the fact that internet recover would be running from Sierra which does not understand APFS.

There is 22.46GB of “Other Volumes” showing up within my MacintoshHD - is this normal for the Fusion Drive?

Any thoughts on what to do next to try and get something running again?

Thanks.

Boot into Internet Recovery (Shift + Option + Command +R) and choose Disk Utility. Your Fusion drives will likely be highted in red font now which indicates the file system was "damaged" (actually just converted to an APFS container.) Highlight either drive (it doesn't matter) and a new DU pop-up window will appear asking if you'd like Disk Utility to repair your fusion array. Select yes. (This repair erases and formats both drives and restores a fused array with a single volume named Macintosh HD running HFS + and ready for the original OS install in the next paragraph below)

Once the fusion drive repair has completed quit Disk Utility and choose "reinstall macOS" from the primary MacOS Utility screen which will download the original version of macOS that came on your machine from Apple. Let the download and operating system complete as it will restore your original *firmware as well as the original factory operating system. After it completes and you are at the setup screen as it came out of the box you can setup your mac as new or shut down and boot into macOS Recovery (Command + R) and enter Time Machine and recover your last system image that had Sierra (10.12.x, etc) with your apps and data intact when that snapshot was made.

This is how I've recovered from the earliest betas of High Sierra running APFS when all else failed on my late 2014 5K iMac.

* it's important to let the original OS and firmware install as you may find like I did that the HS firmware hosed "Find My Mac" on my 2014 5K iMac after recovering using macOS Recovery or a TM backup and none of Apple's solutions for a fix repaired or restored Find My Mac. FMM was left deactivated after each of those recovery attempts to 10.12.6 so I wouldn't have been able to track it online had it been stolen. Reinstalling the original OS using Internet Recovery first restores the firmware as well as the orginal OS and Find My Mac to full functionality and it's easy enough to upgrade the OS later from the App Store or a TM backup of 10.12.x with your apps and data intact.

NEver could get this to work whether booting from recovery USB or internet recovery. Even a fresh install would allow the SSD (OWC PCiE SSD) to be formatted as APFS BUT as soon as I went to install it would start the intiial copy then on the first reboot would boot to the no entry. GOing into Disk Utility again wouldnt allow a First Aid on that drive. Not sure what is going on but it is repeatable for me. Raising bug.

Had the same problem (convert to APFS -> reboot -> no entry screen).
I googled for it (Mac: Converting Boot Drive from HFS+ to APFS Including Boot Repair
) found a video and followed the instructions there (using a usb installer for disk utility)
This finally creted/fixed the preboot section on the APFS volume.