If you cannot access your hard drive due to The drive protected by BitLocker is already unlocked error, use these proven fixes.

Bitdefender has released a decryptor for the 'ShrinkLocker' ransomware strain, which uses Windows' built-in BitLocker drive encryption tool to lock victim's files.

If you see This PC doesn't support entering a BitLocker recovery password during startup, enable WinRE, tweak Group Policy, verify TPM, recreate the recovery partition, etc.