Bitlocker or Encrypted File System (EFS)? I got the error message “Back up your file encryption certificate and key” out of nowhere. Strange, I use Bitlocker and I think OneDrive for Business uses Encrypted File System (EFS) in Windows. If this is necessary, why have not I seen this message before? After some Googling, I … Continue reading FIX: Back up your file encryption certificate and key by Bas Wijdenes