One single typo equals a lot of trouble for users
Shortly after the rollout of Chrome OS 91.0.4772.165, lots of reports starting hitting the web about bricked Chromebooks. A nasty bug broke the authentication system, causing Chrome OS to reject passwords on the login screen.Android Police reports the root of the problem is a small typo in a conditional statement in a method used by the authentication system. A Google developer accidentally forgot to add a second "&" in the source code. This bug broke the decryption system and made it impossible for Chromebook users to login.
Fortunately, there's already a new update to resolve the problem. Users can be reassured that Chrome OS 91.0.4772.167 is safe to install.
Chrome OS 91.0.4772.167 is now available on the update server, which should finally close the curtains on this serious issue. With the new build, Chrome OS should be able to decrypt your user account and sign you in, allowing you to access your important files.Instructions on how to resolve the issue can be found over here. If you installed the update and are stuck on the login screen, or your device is bootlooping, an intervention may be needed. The link has information on how to proceed.
The bug reveals Google's quality control of Chrome OS releases is far from perfect. It's kinda astonishing that this bug slipped past three developers channels and got rolled out to millions of users.