How to Fix Installation Issues for macOS Sequoia on Late 2012 iMac (iMac13,1)

Troubleshooting macOS Sequoia Installation on Late 2012 iMac

If you are encountering errors or boot loops when trying to install macOS Sequoia on a Late 2012 21.5-inch iMac (iMac13,1) using OCLP, it is usually caused by outdated patch settings or a corrupt USB installer.

Step-by-Step Fixes

1. Recreate the Bootable USB: A common culprit is a corrupted installation medium. Use a high-quality USB 3.0 drive, open OpenCore Legacy Patcher, and recreate the installer from scratch.
2. Disable Incompatible Settings: Open OCLP, go to Settings, and make sure settings like 'Show Boot Picker' are enabled so you can troubleshoot. Ensure the target model is explicitly set to iMac13,1.
3. Rebuild OpenCore: Click 'Build and Install OpenCore', and write it directly to the EFI partition of your USB installer.
4. Reset NVRAM: Shut down the iMac. Turn it on and immediately hold Option-Command-P-R for 20 seconds. This resets the hardware environment, clearing out old macOS boot variables.
5. Apply Root Patches: Once you successfully reach the setup screen and boot into Sequoia, open OCLP and run the 'Post-Install Root Patch' to apply essential graphics acceleration patches.