Here's a variation to the problem. I too turned on FileVault because I came across an article advising that I do that. And like many here, I also was not issued a recovery key. I had chosen the option to get access with my login password. But on investigating the matter further, I found instructions per Apple are that you will need a login password and your recovery key should you restart your computer, which we all need to do from time to time. I was concerned now that once I restarted my computer, I would not get access. I do have a backup, and if my iMac crashed, I imagine I could restore via TimeMachine. However, the host of uncertainties was enough to make me turn off FileVault and research the matter more.
I came across this suggestion which sounds great, but it pulled a strange one on me. By that I mean that Terminal never asked for a password for "/". Instead I got: "Enter a password for '/', or the recovery key:" I entered my password and got: "[MY-NAME]s-iMac:~ [my name]$". Does that mean that my login worked?
Another question: During this "crisis," I dug through my old logs from way back when this iMac had Lion and found, of all things, a FileVault recovery key. Has my iMac been keeping that key through all my upgrades?
Yet another question: My computer said that while my iMac was turning off FV, I could use it to do stuff, so I tried using Terminal to disable that old key. When I entered the command to disable I got ".Error: couldn't start decryption: err = -69755" Does that mean it couldn't do that because it was already doing that? Or that I couldn't use Terminal at that time? Or because of something else?
Any information anyone can provide will be much appreciated. I'm wondering if I should use that key or disable or doing something else. I feel like I'm in FileVault limbo.