I turned on my MacBook Pro for the first time since about 4 years. Instead of going to the account screen, the Mac showed a choose-your-language screen and then the OS X Utility. It seems that there is no data on the hard drive (except for ~300MB in Other) according to Disk Utility. I also did First Aid on the hard drive, but no error was found.
I restarted the Mac with the Startup Option by pressing the option key, and the only available disk is called “Recovery-10.11.4”.
Is the data actually gone? Is it possible to recover the data and /or account? Thank you for your help!
Thank you so much for the reply. No, I did not have an USB stick plugged into the Mac. I still can't figure out a solution (if there is one). I have learned that OSX 10.11.4 had data loss issues though. Since the only disk available was called "Recovery-10.11.4" when I restarted the Mac with the Startup Option, maybe this version is the cause. Any more suggestion is appreciated. Thank you.
My friends just brought me a 2009 15" MB Pro, it was having a similar issue. It would get stuck on the grey loading screen. I tried using a bootable USB to get into recovery options and used the terminal to navigate through the files and I was able to see that he had saved files on the HDD so it was letting me read files from the OS.
I asked him if he had anything important he said no so I proceeded to doing a clean install but had no success. First Aid found no errors on the drive. I took the drive out and connected it with External bay to my Windows machine and did a low-level format to see if that would fix the issue but it still wouldn't let me install the OS.
I have an old HDD that has macOS installed and plugged it in to the machine and it worked. At that point I knew that the HDD he had was just done.
Moral of the story is maybe your HDD is just bad and it acting weird because it doesn't know what else to do just like the HDD on my friends laptop.