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macsync3 Author

Level 1

38 points

Unable to install High Sierra

After downloading High Sierra to my iMac (which takes around 1 hour) I select the hard drive to install it on and a message on screen says calculating installation time. After a few minutes I get a black screen with a white circle with a white diagonal line through it (no entry sign) Restarting using command + R and selecting reinstall Mac OS Sierra works fine all back to how it was. Apple support do not have an answer for this issue, anyone had the same problem and hopefully a fix.thanks.

iMac (21.5-inch, Late 2013), macOS Sierra (10.12.6)

Posted on Nov 17, 2017 3:04 AM

18 replies

macsync3 Author

Level 1

38 points

Nov 20, 2017 12:36 AM in response to thirtyyears2015

Hi, I have erased the hard drive and restored but not reformatted, I don’t understand how Sierra is working perfectly if there is an issue with fusion drive 🤔

Eau Rouge

Level 8

42,554 points

Nov 20, 2017 1:16 AM in response to macsync3

Your drive probably is formatted properly as you can install Sierra on it. Use Disk Utility to check if you want to allay your fears.

This is a tricky one.

macsync3 Author

Level 1

38 points

Dec 7, 2017 7:49 AM in response to macsync3

Hi, Just to let you know I have installed 13.2 without a problem, thanks for all your help.

Unable to install High Sierra