I run two google chromes and updated both to the latest beta version (Version 59.0.3071.29 (Official Build) beta (64-bit)) and Canary version (Version 60.0.3082.0 (Official Build) canary (64-bit)). Both were working with the latest 1Password extension, but since the update they fail to autofill because "Browser could not be verified". I tried to update to 1Password extension to its beta release, and it cannot autofill with the same reason.
I tested my setup with Firefox 53.0 (64-bit) and Safari Version 10.1 (12603.1.30.0.34) which are both autofilling as expected, so it seems like a browser issue.
1Password Version: 1Password Version 6.6.4 (664002) Mac App Store
Extension Version: 1Password Beta 126.96.36.199
OS Version: macOS 10.12.4 (16E195)
Sync Type: Not Provided