I am using Ubuntu 18.04.2 LTS and Firefox 65.0.1 (64-bit), and the 1password extension does not work. Clicking on the 1password icon opens up a new window, which remains empty.
Below please find a screenshot with the error message from the console included.
1Password Version: Not Provided
Extension Version: 1.14.2
OS Version: Ubuntu 18.04.2 LTS
Sync Type: Not Provided