macOS 10.13 High Sierra problems: how to fix them

Welcome to our continually-updated list of macOS 10.13 High Sierra problems. Not only do we list the most common macOS High Sierra problems, we also have their fixes, so you can have your Mac up and running again as quickly as possible.
Due to how new macOS High Sierra is, we may not have covered all of the problems, but we will continue to update this guide as new macOS High Sierra problems are reported.
If you’ve encountered a macOS High Sierra problem that we haven’t covered, follow and tweet us and we’ll do what we can to find a solution.
From macOS High Sierra installation problems, to security risks and issues with making apps work, read on to find out how to fix the most common macOS High Sierra problems.

macOS High Sierra won’t download

A common macOS High Sierra problem at the moment is that macOS 10.13 begins to download, but then it pauses along with an error message that says “macOS High Sierra download has failed”.
Another common macOS High Sierra download problem shows the error message: “Installation of macOS could not continue. Installation requires downloading important content. That content can’t be downloaded at this time. Try again later.”
There are a few reasons why you may get this problem. It may be because a lot of people are trying to download macOS High Sierra at the same time. If this is the issue, try again later to see if the download now works.
It may also be worth switching from a Wi-Fi connection to an Ethernet cable, to ensure your internet connection is as reliable as possible.
If you’re still having problems downloading macOS High Sierra, try to find the partially-downloaded macOS 10.13 files and a file named ‘Install macOS 10.13’ on your hard drive. Delete them, then reboot your Mac and try to download macOS High Sierra again.
If you still have a problem downloading macOS High Sierra, open up the App Store, click ‘View My Account’ and see if there is anything in the ‘Unfinished Downloads’ section. You may be able to restart the download from there.
Finally, try logging out of the Store to see if that restarts the download.

macOS High Sierra install problems

If you’re having problems installing macOS High Sierra, first make sure you check out our how to download and install macOS 10.13 High Sierra guide, which will take you through the steps you need to take to safely install the new operating system.
If the macOS High Sierra download completes, but there’s no prompt for the installation to continue, then search in your Mac’s application folder for a file called 'Install macOS 10.13'. Double-click the file to begin installation.
You also need to make sure that there is enough hard drive space on your Mac, otherwise the macOS High Sierra install will fail.
To fix the macOS High Sierra problem where the installation fails due to low disk space, restart your Mac and press CTL + R while it’s booting to enter the Recover menu. Select ‘Disk boot’ to boot normally, then remove any files you no longer need.

If you’re struggling to free up disk space, look out for hidden Time Machine files that may be taking up large amounts of space.
Once you have freed up enough space, retry the installation.
If macOS High Sierra encounters a problem at the end of installation, and then shows an error message, restart your Mac and press Command + Option + R on your keyboard while the Mac boots to start up the recovery system over the Internet. You can also try Shift + Option + Command + R.
If your Mac continues to fail to boot, follow Apple’s instructions on creating an external Mac startup disk.
It may be worth restarting your Mac in Safe Mode, then trying to install macOS 10.13 High Sierra from there to fix the problem.