HELP!!! Disk Encryption failed with the error: ...

I am trying to reset a macbook pro for a family friend that is stuck at the apple logo at start up. When I go to reformat the hard drive I just get an error Disk Encryption failed with the error: Couldn't eject disk. I have no idea what to do, I looked it up and one really has a fix for this problem.

Anything helps, Thank you.

最后更新：2017-08-25 10:53:53