Big Sur 11.2.3 doesn't update?

Hi fazze,

Thanks for your post in Apple Support Communities. If your iMac is having issues updating to the latest version of macOS Big Sur, 11.2.3, there are some steps to help.

If you receive any type of error message, that can help indicate what might be the underlying cause. Make sure you have a stable network connection. If you were using Wi-Fi, try an ethernet connection if possible. Try disconnecting any external hard drives, audio devices, or other peripherals prior to trying the install and see if that helps. Also check your available storage. Click on the Apple menu () > About This Mac > Storage.

If you still haven't been able to update, create a test user profile with admin privileges, log in to it, then try the update again.

Set up users, guests, and groups on Mac

Best regards.

Try the following: go to the App Store, search for "Big Sur", download it and install.