If you session password doesn't work upon activating Bitlocker, this may be due to the fact that your current session password is not compliant with your company's agreed-upon security policy.
In this case, we invite you to log out of your session and try log in again and choose a password respecting the following criteria:
- minimum 10 characters
- with at least an upper case letter, a digit, a special character in addition to lower case letters