Update, July 20 (5:15 p.m. ET): Version pulled, new update rolling out on Wednesday, July 21

What you need to know

• Reports of issues started flooding as Google pushed out Chrome OS update 91.0.4472.165 today.
• Impacted users cannot log back into their Chromebooks, so do not update your Chromebook.
• If your Chromebook asks to Restart to update, do not click Reboot and do not shut down your machine.
• Google is aware of the problem, and a fix should be deployed soon.
• If you're already locked out, you'll have to Powerwash your Chromebook to get back in. If your device is bootlooping before you can get to the lock screen, recover using a USB drive and the Chromebook Recovery Utility.
• This is the second critical bug on the stable Chrome OS channel in less than a month.

Somehow, a major bug has slipped through three experimental channels and made its way into a Chrome OS stable channel — AKA the channel that the vast, vast majority of Chromebook owners are using. This bug is in Chrome OS 91.0.4472.165, and it is not allowing users to log back into their Chromebooks after the update, and in some cases, their laptop is bootlooping so they cannot access the lock screen. In these cases, you'll need to create a Chromebook Recovery USB stick using the Chromebook Recovery Utility and use that to re-image your Chromebook.

If the update has downloaded but installation has not finished, do not shut down your Chromebook. The update will install on your next reboot or system shutdown.

Google seems to be aware of the situation and should be working on a fix soon, but the update hasn't been pulled yet, it seems, so don't go to the About Chrome OS screen, do not check for updates, and do not shut down your Chromebook if you can help it.

Users who unfortunately got the update first are currently locked out of their machines, at least until they Powerwash them. Once impacted users factory reset their Chromebook, they can set it back up and get back in, but keep in mind this is a factory reset and will erase all local data and the Linux program data. If you can wait for a fix, you might be able to wait and then update your Chromebook from Guest Mode, but we have no timetable for a patch.

We're reaching out to Google to ask when they might have a timeline for the fix and how this has happened twice in such a short amount of time. We'll update this story as things progress.

Update, July 20 (5:15 p.m. ET) ― A fix is coming on Wednesday

Google has posted a status update on the issue, saying that the company has identified the cause. While Google doesn't go into specifics, the company says that "a new version which will fix the issue will be available on July 21st."

For users already affected by the bug, Google lays out two options to update to the new version:

• Leave the Chromebook device on the login screen to download the update via auto-update.
• Update the device manually after logging into Guest Mode.

The updated Chrome OS version should arrive by EOD Wednesday, so affected users can either hold tight, Powerwash their device, or roll back to the previous version via USB.