How To Update Macos High Sierra 10136 To 1015
Fix: Change system date temporarily via Terminal:
You can skip Mojave entirely – the Catalina installer works directly from High Sierra.
Some Macs on High Sierra can directly install macOS Big Sur (11) or Monterey (12) without installing Catalina first, provided they meet hardware requirements.
Check your Mac’s maximum supported OS:
To get a newer OS: Search App Store for “macOS Monterey” or “macOS Big Sur.” If the installer allows it, download and run directly from High Sierra. If not, the installer will tell you to update to an intermediate version (Catalina).
Updating from High Sierra to Catalina is a straightforward process via the Mac App Store, provided you have verified hardware compatibility and backed up your data. However, the loss of 32-bit app support makes this a "point of no return" for users reliant on older software.
Title: The High Sierra Ceiling
Elias rubbed his temples, staring at the glowing screen of his trusty MacBook Pro. For years, it had been a loyal soldier, running macOS High Sierra (10.13.6) without complaint. But the digital world had finally caught up with him. The warning message on his banking app was blunt: “Your browser is no longer supported. Please update your operating system.”
He clicked the Apple logo in the top-left corner, navigating to "About This Mac." The window confirmed his fears. He was stuck on 10.13.6, and he needed to get to macOS Catalina (10.15).
"Easy enough," Elias muttered. He opened the System Preferences pane, expecting to see a "Software Update" button that would whisk him away to the newer version. how to update macos high sierra 10136 to 1015
He clicked. The wheel spun. And spun.
Finally, the window appeared. No updates available. His Mac insisted that High Sierra was the latest and greatest.
"That can't be right," Elias said, pulling out his phone. A quick search confirmed his suspicion. The jump from High Sierra (10.13) to Catalina (10.15) was a "major version leap." While minor updates happened automatically in the background, major leaps often hid behind a wall of compatibility checks and specific App Store listings. High Sierra was the last version to support 32-bit apps, and Catalina was the first to cut them off completely. Because of this, Apple didn’t always push the update aggressively.
Elias took a deep breath. He knew he had to be careful. He plugged in his external hard drive and ran a Time Machine backup. "Better safe than sorry," he whispered, watching the progress bar fill up.
Once the backup was secure, he opened the App Store. He didn't search for "Catalina" directly at first; he had read that sometimes the search results were buggy. Instead, he used a specific trick he’d found online. He searched for the link to the macOS Catalina installer via Apple’s support pages.
When he clicked the link, the App Store flickered and loaded a page for macOS Catalina. The "Get" button stared back at him.
He clicked it.
"Are you sure you want to download macOS Catalina?" the prompt asked.
"Yes," Elias confirmed.
The download began—a hefty 8 GB file. Elias watched the progress bar under the Launchpad icon. It was slow, agonizingly so. He went to make coffee, then came back. It was at 50%.
"Come on," he urged the machine.
Finally, the download finished, and the macOS Catalina Installer window popped up automatically. It asked him to choose a disk to install. He selected his Macintosh HD.
The computer restarted. The screen went black, followed by the familiar Apple logo and a progress bar.
This was the moment of truth. Elias knew that upgrading an older file system like HFS+ (which High Sierra often used for spinning hard drives) to APFS (Apple's modern file system) could take time. The bar moved slowly.
One hour remaining.
Elias paced the room. He thought about the 32-bit games he used to play—games that wouldn't work after this update. It was the price of security.
Thirty minutes remaining.
He sat back down. The screen flickered as the firmware updated. Fix: Change system date temporarily via Terminal: You
About a minute remaining.
The bar filled up. The screen went black again, then burst into a "Welcome" animation in multiple languages. The setup assistant appeared. He selected his region, signed in with his Apple ID, and agreed to the terms.
The desktop loaded. It looked cleaner, brighter. He clicked the Apple logo once more.
macOS Catalina. Version 10.15.7.
Elias smiled. He opened his browser. The banking site loaded perfectly. No warning messages.
He had crossed the bridge. His Mac was modern again, ready to face the internet for a few more years. He ejected his backup drive, satisfied with the work well done.
Since macOS Catalina is an older version (preceding Big Sur, Monterey, Ventura, and Sonoma), it is located in the "Older Versions" section of the App Store.
Catalina requires at least 20 GB of free space, but 30–40 GB is safer.