I got this problem, and I have done the most stupid thing by clicking the "reset phone" button, and it never went back to the main screen after that.
I have flash another rom and it was working funny, so later I decided to try this one again.
It was running okay at the first beginning, but after I reboot the phone, "encryption unsuccessful" appeared again.
So I went to recovery mode and reset factory data reset, and reboot again, it worked fine.
But when I reboot again, the same problem came.
So I just switch off the phone and start it again, and it's working fine.
I have googled it and it seems a lot of people got the same problem, and they just avoid to reboot the phone.
So would it be the problem of kernel? or it's the usb storage?
Is there any way to fix it?