I was also having this same problem.
New updated process
1. Restart your Mac and hold down the Command + R keys at the same time right after you hear the chime
2. When the boot completes you will see the OS X Utilities window. Do not select anything in this window.
If your harddrive is locked/encrypted, you need to perform A-B before moving on to 3
A) Open Disk Utility
B) Click on and select your Logical Volume, under the Internal Disk (it's greyed out). Mine is "Macintosh HD"
C) In the menu bar, Choose File > Unlock.
D) In the menu bar, Choose Disk Utility > Quit Disk Utility.
3. In the menu bar select Utilities > Terminal
4. Type resetpassword (no space between the words) and press Return on your keyboard
5. In the new window that opens, select your Macintosh HD and enter your new password (and hint if you choose)
6. Select Save
7. Select OS X Utilities > Quit OS X Utilities from the menu bar
8. This will prompt you to restart your Mac
9. After restart, enter your new password to log in