The reasons for this reversal can be many. It is usually related to problems with the current version of an app that you use on a recurring basis, or for some problem with any connection hardware type. Peripherals that are not yet adapted to the latest version of macOS present or for no apparent reason, revert to the High Sierra version as it is a more stable version.
Going back to the previous version of macOS High Sierra is not difficult, but it requires several steps and time to download the software and install it. For this we must carry out different steps.
First of all, tap download the macOS High Sierra software. We must go to the Mac App Store. If you search for macOS High Sierra from Mojave, it will not appear. This is because Apple does not provide an operating system older than the one currently installed. But it is found, if we go to our purchases, within the Mac App Store. Click download, on the right side.
As it is not an executable file, we cannot just install it. In this case, we can rely on a previous version of Time Machine backup, which we have done with High Sierra installed. The last option is to save the file that we have downloaded to an external disk and perform a clean installation. This option is recommended in the case of taking a long time without being done, that is, version after version, or we install and uninstall many applications. You must bear in mind that the clean installation removes all the content of our equipment, you choose which option is best for your interests.
3 comments, leave yours
The High Sierra or any previous operating system does not appear in the purchases section of the mac store.
I was taken by this unpleasant surprise, after trying and seeing that Mojave has many bugs with multimedia applications, I decided to go down to High Sierra, which used to work wonders, and now I cannot download the image to perform a clean installation. It only downloads a 22 Mb executable that it then performs a rear download and then installs on Mojave, and that is not what I want. Apple increasingly applies policies more similar to "state politicians" leaving aside users who pay their salary ...
Avoid buying IMAC RETINA 21,5 inch 4K 2017, it is very slow but the worst thing is that it is NOT possible to make a backup copy the files are of the APFS type, on an external hard drive whatever it is and even the Mac Capsule, I have an older Mac with the High Sierra installed and it works like a charm compared to the Mojave, of course if you try to upgrade to Catalina and you don't see what you do, I'm sorry to make this purchase