I'm using Windows 10 with Chrome. This is a new error. Chrome is up to date and I restarted the PC.
I realise I am using an old version of 1Password. I paid $48.99 for a family license in October 2014. I'm therefore not on the subscription model. The Chrome extension also no longer works but I assumed that was related to not being a subscriber.
1Password Version: 18.104.22.1686
Extension Version: Not Provided
OS Version: Windows 10
Sync Type: Dropbox