SmittyATL Said:
"Macbook Pro won't boot: I had the beach ball of death earlier and did a hard restart of my computer (a 2012 macbook pro). It was stuck on the Apple screen forever. I tried to boot into safe mode and it couldn't. I reset the Pram several times and it still didn't help. What else?"
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A Few Thoughts:
Perform the following in the order provided here:
Recovery Mode (hold [command+R] upon boot), and select the hard drive, and click the Mount button, and then click the First Aid button. This is performed in Disk Utility of Recovery Mode.
Boot into Recovery Mode (hold [command+R] upon boot), and restore from a Time Machine Backup?
Install from a USB Bootable Installer - Particularly, one that boots into Mojave (Which you seem to be using). Hold Down the option/alt key to boot to it. With permission, use another Mac (yours or a friend's, family member's or coworker's).