Sep 17, 2021 If the App Store says ‘Open’ then it is detecting a previous download of the install app. Go to the Applications folder locate Install macOS.app. Move it to the Trash, empty the Trash. Restart, click on the link again, the App Store should say ‘Get' or 'Download'. If you want to or are able to install Big Sur, open Safari and click. Basically, the firmware update is copied to the FAT32 formatted EFI partition. The firmware is then instructed to update itself. Basically, the same procedure occurs for firmware updates on my HP PC running Windows. So, this is not unique to Apple Macs. Having to update the firmware to run High Sierra makes sense. Removing the original High Sierra 10.13.6 from the Apple Store and replacing it with a convoluted process, with a version that has security updates in place, that prevents the 'usual fix/hack' of applying Combo Update 10.13.6 over the top, from working, and thus applying any necessary firmware/file permission changes. Tutorial on how update to High Sierra Os from later model mac pro 2011-2012 with pre-installed Lion X 10.7.5.
If you're having difficulty finding or installing updates:
Haven’t joined the bandwagon and upgraded your macOS from Sierra to High Sierra yet? Good thing you’re reading this article before you do because we have some important reminders and tips that might help you ensure a smooth transition from Mac Sierra to High Sierra.
MacOS High Sierra is basically an improved version of the Sierra. It was developed mainly for software refinements, thus the tagline, “Your Mac. Elevated.” However, it also lays the foundation for additional features like virtual and augmented reality (VR and AR).
High Sierra offers several neat improvements, included are these four upgrades, we think, are the most noticeable:
Updating to High Sierra is free and with all the features and upgrades it comes with, this shouldn’t even be a question. But if you’re still not convinced, below is a checklist to help you decide. If you say ‘yes’ to these, then you should definitely consider going for the update.
Pro Tip: Scan your Mac for performance issues, junk files, harmful apps, and security threats
that can cause system issues or slow performance.
With all your yeses, try to hold your horses, first. Before you even download macOS High Sierra, you need to be sure that your Mac’s up for the update.
Before you get all excited and hit the upgrade button, you should first make sure if your Mac’s current specs can run the new macOS. If your Mac can run Sierra, it is highly compatible with High Sierra. Below is a list of the compatible devices:
You can also determine your Mac’s pedigree by going to Apple menu > About This Mac. A window will open, showing your Mac’s information.
Apple recommends having at least 8.8 GB of free disk space to accommodate the High Sierra upgrade, but to ensure that everything runs smoothly, you’ll need more than that. And if you have just enough disk space to install High Sierra, you seriously need to consider cleaning up your drive. Sure, macOS High Sierra might install fine, but if it doesn’t have space for temporary files and caches, you are likely to run into problems later on.
So, before you download and install macOS High Sierra, take a look at your hard drive and delete or move some files. It’s best to delete old and unused temporary and cache files, too. To help you do that faster and easier, try running a 3rd party cleaning tool like Mac repair app. It will scan your disk for junk files that are eating too much space, allowing you to get rid of them with just a click of a button.
Before performing anything major on your Mac like upgrading to a new OS, it is necessary to create a backup. You can use the machine’s built-in Time Machine, but we also recommend backing up to another external device or another program. Having two backups creates a safety cushion in case one of them gets corrupted.
If there are programs or apps that you are currently using and probably will be using after the upgrade, check with the developers of the apps if they are already compatible with macOS High Sierra or if an update has already been released.
You also need to check compatibility for helper apps and drivers, as well as the software required by any of your unit’s hardware and peripherals. Some utilities might need to be updated, too. To be safe, update all of these first before upgrading the macOS itself.
While macOS High Sierra certainly proves to be an excellent upgrade, you have to make sure that your Mac, its drive, and the programs and software you use are prepared for the change.