I keep getting an error while installing MacOS Big Sur on a MacBook air 2017 128GB, here are some thing I already tried
I get a message "An error ocurred loading the update" at minute 17.
I finally got my computer working I had to do a clean install of the OS X version my mac was pre-installed when brand new. I followed the setps provided by Kappy on this thread https://discussions.apple.com/thread/8159972
From what you have described, I have to assume that you have tried to install several downloads unsuccessfully. I would have to ask if you did place the "old" earlier downloads in the Trash and empty it? Otherwise, maybe the computer keeps trying to reinstall the same corrupted download. I would ensure that all Big Sur downloads are trashed and then do a clean one not using Wi-Fi. That can cause corruption as it is too slow for these very large files. Use a wired Ethernet connection for your download and see what happens and good luck.
The Internal Drive is quoted as a 128 GB Drive. Therefore the immediate question is - If upgrading from macOS Sierra or later, your Mac needs 35.5GB of available storage to upgrade. If upgrading from an earlier release, your Mac needs up to 44.5GB of available storage. To upgrade from OS X Mountain Lion, first upgrade to OS X El Capitan, then upgrade to macOS Big Sur.
Try the following: boot into Safe Mode, go to the App Store and download the full Big Sur installer and run it in Safe Mode. It will be for the latest version.
Good work :-)) and the log way back to El Capitan just to get the machine working again.
Error while installing macOS Big Sur "An error ocurred loading the update"
