Chrome OS Version: Version 67.0.3396.26 (Official Build) beta (64-bit)
Chrome OS Platform: 10575.22.0 (Official Build) beta-channel eve

Steps To Reproduce:
(1) Chrome OS device on beta channel
(2) Update to 67 Beta
(3) Restart device

Expected Result:
Boot into Chrome 67

Actual Result:
A screen saying that your device is applying a critical update do not turn it off followed by the "Chrome OS is missing or damaged" screen.

How frequently does this problem reproduce? (Always, sometimes, hard to
reproduce?)
On update to Chrome OS 67 beta

What is the impact to the user, and is there a workaround? If so, what is
it?
Power cycling the device at the "Chrome OS is missing or damaged" screen got me back to the login screen but users may be afraid to restart the device given the warning on the earlier screen or may wipe the device by pressing ctrl+D at the "Chrome OS is missing or damaged" screen as they think the OS is damaged.