MacBook Pro 2012 HD locks on boot Today my laptop has started to lock the HD. When booted it either stays black with the fans going nuts or it loads up a dialog to reset pw. In this window I can choose startup disk from the top left menu. The dialog that opens allows me to unlock the HD but the system needs to reboot to use my HD as startup disk. And then it starts all over again...

I've also tried both pram reset, Smc reset and verifying/repairing the HD in disk utility. It still keeps locking the HD when booting up.

Any other suggestions?
I got the machine to boot by starting up in recovery mode and turning off encryption on the drive in mention. Not sure what the implications of not being encrypted is though...

useful links:

https://support.apple.com/en-us/HT201255

https://derflounder.wordpress.com/2011/11/23/using-disk-utility-to-unlock-or-decrypt-your-filevault-2-encrypted-boot-drive/