I just noticed this started recently on my old iMac (still running El Capitan) with 1Password 6 (stand-alone). I have a family membership but on this old iMac, I still use the 1P6 standalone version with Dropbox. I know, I need to upgrade to at least High Sierra so I can start using the Family membership, but I just haven't gotten around to it yet, and I only use the iMac on rare occasions. But it has always worked in Chrome and now it has stopped working. I can still run the app and the mini in the menu bar, but not in Chrome.
When I look at my extensions I see:
Is there any hope?
1Password Version: 6
Extension Version: Not Provided
OS Version: OSX 10.11