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High Sierra installation failed

My wife has a MacBook Air, with OS 10.9.5. Tonight I tried to update it to the High Sierra 10.12.6, but in the process of this, there were problems with her PW for her Apple ID. After we resolved this, I again tried to install High Sierra but now the App Store says that it's already installed. But that's wrong, because with About This Mac, I still see OS 10.9.5 .

This is really strange. Does anyone have an idea about how to fix this?

Posted on Aug 8, 2018 11:04 AM

Best reply

Kappy

Level 10

361,741 points

Posted on Aug 8, 2018 2:11 PM

In the Applications folder look for the downloaded installer, Install macOS High Sierra. If it is still there then double-click on it to start the installer.

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High Sierra installation failed

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