I use Chromium, and was presented with the "1Password can't save or fill" issue, which I resolved according to the instructions for Canary/Vivaldi. I am no longer presented with the error message, but now it appears 1Password and Chromium are not talking to each other. Both 1Password Mini and the Chrome extension do not recognize any content within Chromium, and the extension does not allow me to navigate the submenus for entry access (see attached image).
The extension in Safari is working without issue at present, so this appears restricted to (at least) Chromium (official build 61.0.3147 as of this writing).
1Password Version: 6.8
Extension Version: 184.108.40.206
OS Version: OS X 10.12.5
Sync Type: Not Provided