High Sierra install issues and now can't find startup disk

I also need help, I downloaded the update High Sierra on my 2012 macbook pro and ended up with the ? in a folder after failing to download. i have tried to do the Command+R so that it can go into the Recovery mode, went to the Disk Utility and i found on the left there is Internal (APFS Volume. - Encrypted) and there is also Disk Images (OS X Base System - Disc Image volume.Mac OS Extended)

I unlocked the APFS Volume with my user password and did the first aid then proceeded to start up disk where it says choose start up disk, no disk is displayed there.

If I select the OS X Base on DIsk images (Disk Utility) and do first aid, it says - First aid needs to temporarily lock the boot volume. I press continue and takes just under 2 mins to finish with first aid. if you go to start up disk it gives Encrypted disk. i selected it and at the bottom says The disk " " is encrypted - It must be unlocked to determine if it is a valid startup disk. Entered my password to unlock and the disc disappeared meaning i can not restart.

KHFS instructions worked for me too. No data was lost. After installation was completed, it booted to my wife's username and logged in just fine. My wife says thanks. 😉 Now we will be sure to have 3 backups in the future...

Hi,

I just found your post after the same thing happened to me. Tried "upgrading" to High Sierra and now my MacBook Pro is in an unuseable state!! Initial problem was it couldn't find file OSInstall.mpkg but then I also couldn't restore from my Time Machine because it can't erase the disk because I don't think it can see one!! If I try to use the startup disk utility it doesn't see any hard drive?!!!?! What was the solution to your problem at the Genius Bar?

Thanks

When you say you clicked on the apple and chose the boot disk? I assume you mean Startup Disk? This is the only option I can see when booting up in recovery mode. Then, after selecting Startup Disk, it asks me to choose the Startup disk yet none are displayed, so I'm not sure how yours managed to reboot??? Which OS version did you upgrade from? I still had 10.9.5 (Mavericks) so maybe that's cause an issue trying to upgrade to High Sierra ie if you already had Sierra, maybe it's not such an issue?

Ok thanks for letting me know. You'd think the install process would check the existing OS version and only proceed if it supported the High Sierra update, otherwise instructing you to install El Capitan (for example) first.

Oh well, in future if I leave it a while before updating OS I'll check the forums first!!

Can your Mac startup normally now?

I am getting exactly the same problem.

I have tried all troubleshooting and no good with any of them.

Have you had any luck?

Same here. Hoping someone can tell me how to fix it without having to go into an Apple store, especially since I just bought my 2017 MacBook Pro 3-4 months ago.

Same problem. Took forever to get it to boot into Recovery Mode. I tried to reinstall the OS and now it says "Access Denied."

Hi! Did you manage because I'm getting the same exact problem. Startup Disk completely disappeared.

When I try to do as Badietrich suggests (I tried restore from backup image on my local cloud), I get no disk to recover to, as if no disk is installed. Also, flash USB boot drives are not recognized.

How do I start my Mac after it’s frozen on downloading sierra?

Thanks for sharing!