I have a fresh install of Firefox beta 60.0b14 on macOS 10.13.4. I installed 1Password X 1.6.6. I can't get it to work.
After clicking the extension in the toolbar, it prompts me to sign in with my master password as expected, but after hitting enter on the keyboard, it just shows the spinner forever (or until I switch focus outside of the window). If I go back and click on the extension again, the window is just blank.
In the console I see:
[LM] @startMonitoring (autolock=90) Unchecked lastError value: Error: Could not establish connection. Receiving end does not exist. background.js:1 de/< moz-extension://14d534d4-5c88-a54f-abad-2f01e9351db4/background/background.js:1:556393
Interestingly if I purposefully enter an incorrect master password, I see:
[action/Session#verify] ClientError: Invalid email or password
That suggests there is some communication happening, at least.
Extension Version: 1.6.6
OS Version: 10.13.4