Hello,
Thank you for posting in Microsoft Community forum.
Based on the description, I understand your question is related to enable bitlocker.
The bitlocker encryption process may take a few time, please wait the process to finish. If the process didn't finish or return an error, please record that error code.
Also, you can try reboot machine if there is no response of power on machine with black screen. If reboot into normal login screen, login the machine and run below command to check the Bitlocker status:
manage-bde -status
This will show the status of all drives, whether they are encrypted or decrypted.
Have a nice day.
Best Regards,
Molly