Safari doesn't open, error "server not found" in MacBook Air

Most websites will not work with a Safari version that old. I am not aware of any browsers new enough to load recent websites that will run in Lion.

The best alternative will be to upgrade that Mac to the latest macOS version that it can run.

To do that please follow the instructions in How to reinstall macOS - Apple Support. Specifically, boot Recovery mode using the key chord that will offer to install the latest macOS version compatible with your Mac:

• Option-Command-R: When you press and hold these three keys at startup, Recovery might offer the latest macOS that is compatible with your Mac.

That would be Catalina.

By the way there is no method to uninstall and reinstall only the Safari app, and it wouldn't help if there were.

It's not clear to me what you did. Suffice it to say that no Safari version that can run in Lion will be useful for anything. It lacks the ability to load secure websites. Your goal is to install a newer operating system. If following the instructions I provided did not work then explain the obstacle that you are encountering.

• Option-Command-R: When you press and hold these three keys at startup, Recovery might offer the latest macOS that is compatible with your Mac.

That should work with your Mac. Unfortunately I do not have an identical 2012 model MacBook Air at my disposal, so I won't be able to provide step-by-step instructions with screenshots or anything like it.

Backing up your Mac is a good idea; in fact you should consider it a prerequisite. Upgrading macOS in the manner I described does not delete your files.

What kind of Mac are you using to post here? Whatever it happens to be, you can use it to download the Catalina installer .dmg (file) described in How to download and install macOS - Apple Support.

Scroll down to Catalina 10.15. It will open the App Store and offer the download.

• You can't use the Safari version in Lion to download it because it's too old. That's the reason for using a Mac capable of running a more recent browser.

Once you download that .dmg file, you will need to copy it to your MacBook Air. I suggest using a USB flash drive of sufficient capacity. Drag that file to the Desktop or other convenient location. Then, open it, which mounts the disk image, and launch the installer app.

That should work. I have no explanation for the inability to use the key chord Apple describes in How to reinstall macOS - Apple Support.

Ok thanks. Using the same technique and the same How to download and install macOS website as you did before, download the El Capitan installer. When it finishes downloading, copy that .dmg file to the MacBook Air's Desktop or other convenient location. Open the .dmg to mount it, launch the installer app and install El Capitan.

El Capitan (OS X 10.11) is a required stop along the way from Lion to anything later than that, and would include Catalina. I should have remembered that.

Hi,

It might be security issue since Safari version is too old.

macOS Catalina is the latest macOS for your MacBook Air.

How to download and install macOS – Apple Support (AU)

My mistake for assuming you were using a Mac. The instructions are the same in that they should work with any Mac running a viable browser — certainly one that's more recent than Lion, and possibly El Capitan or newer. Firefox ESR for example will run on El Capitan and should allow that .dmg file to be downloaded.

I'd fix the old dishwasher. Newer appliances are designed to last two or three years, max, and then you throw them out. But that's being "green" so it's ok.

Glad to hear it Tony!

Catalina will extend that Mac's life at least a few years. Like fixing an old dishwasher, it's worth it.