I am working on my macbook pro (2012). I let a colleague borrow it for some work, and they did some weird things with it, but it looked ok when I shut it down yesterday. When I tried to boot it up this morning, it did not load my admin profile for me to log in to, but after about a minute a picture of a file folder with a question mark appeared and was blinking on the screen. After rebooting it several times and then trying safe mode with the same results, I tried to start it in recovery mode with cmd-R (and eventually three other key combinations for recovery mode, but it would only start in internet recovery mode). I can’t use internet recovery right now because my only source of internet is on my phone hotspot, and it won’t even allow me to connect to my phone. Please help.
Reset your NVram
BTW the recovery partition downloads the OS from online, so you're going to want an Internet connection
From apple: How to reset NVRAM
Shut down your Mac, then turn it on and immediately press and hold these four keys together: Option, Command, P, and R. You can release the keys after about 20 seconds, during which your Mac might appear to restart.
On Mac computers that play a startup sound, you can release the keys after the second startup sound. On Mac computers that have the Apple T2 Security Chip, you can release the keys after the Apple logo appears and disappears for the second time.
Also, the blinking question mark means that the drive needs to blessed, which can be done with this tool.
Unfortunately, this requires you rebooting onto an external macOS drive, or connecting to your computer from another mac with firewire 800 and rebooting into target disk mode.
Frankly, soneone you're working with shouldn't be doing anything that screws with your computer up this much, so when you have a chance make sure SIP is enabled (type into terminal
csrutil status). If this is disabled (and you didn't disable it) I'd be concerned.
I hope you have a fairly recent backup in case.