Updated Sierra and iMac Won't Boot

[TheBruno]

After installing a new update on my iMac today (Running Sierra), when it booted there was a cross symbol. Now it won't boot at all. What can I do to fix it?

 

[Fishrrman]

This is why one keeps an external drive with a fully-bootable cloned backup of your (formerly working) OS around. For moments exactly like the one you're having now.

Can you boot into safe mode? (reboot and hold down shift key continuously)

 

[TheBruno]

This is why one keeps an external drive with a fully-bootable cloned backup of your (formerly working) OS around. For moments exactly like the one you're having now.

Can you boot into safe mode? (reboot and hold down shift key continuously)

Yeah, I entered into Recovery Mode, and I'm using a Time Machine recovery before the update was made.

 

[TonyK]

Which update was it so we can keep an eye out and report with our experiences.

 

[TheBruno]

Which update was it so we can keep an eye out and report with our experiences.

After the Time Machine restore, everything is working. Strangely, it was a Safari 11.1 and iTunes 12.7.4 update. I'm reluctant to update it now.

 

[TonyK]

My iTunes was updated a week ago to 12.7.4 and just this morning I updated Safari and security patches for Sierra. It rebooted just fine.

 

[TheBruno]

My iTunes was updated a week ago to 12.7.4 and just this morning I updated Safari and security patches for Sierra. It rebooted just fine.

It's my wife's computer, and her iMac is a 2013 model. It's possible the drive is starting to have trouble, or a file became corrupted after the update. Ever since the Time Machine restore, things are working just fine, and we've rebooted a few times. I'm not sure what the problem is, but since it's just Safari and iTunes, I've suggested she leave it be.

My Late 2012 iMac just went down two weeks ago due to a faulty logic board, and I just spend $3k on a new iMac, so I'm pretty hesitant to drag hers into the Apple Store just yet.

 

[TonyK]

If a restore resolved the problem, that doesn't sound like hardware. My first thought is a corrupted file during the update procedure.