Tutorial to rescue your files with iBoysoft Data Recovery for Mac: To avoid permanent data loss, save your important files now! Watch this video to rescue your data from Mac that can't boot past loading bar: Note that your Mac can't boot up now and any further operations on your Mac may lead to the original data being overwritten. Rescue data from iMac/MacBook that stuck on loading screen Disconnect the peripherals & restart your Mac Then, follow the proven solutions in this post to fix the MacBook Pro/Air or iMac that stuck on the loading screen with the progress bar: So, rescuing data from your Mac is a primary task.
In fact, your Macbook won't turn on at all and froze on startup. But the sluggish progress bar still remains on the screen without any change. You may regard such a long boot process as a slow startup of your Mac and wait for hours. It usually happens after a recent macOS update, like a macOS Big Sur update, or macOS reinstallation.
That is your Mac stuck on the loading screen for a long time.