Dear support team,
I have a similar issue as the one experienced by user aramburo on Oct 2014.
I have 1 password on my macbook pro from more than one year and since 1 week Autofill suddenly does not work.
When I open1 password mini, I got an option "add Safari extension". I download and then click install....then there is no other window appearing. However at this poiint Autofill works. If I close Safari and then re enter I have the same issue.
Moreover 1password safari extension never shows in the Extensions panel under System prefrences.
1 password 5.3 MAcApp store
I tried to check the proxy Http settings but when I select Proxy Http under Preferences/Network/Proxy there is no host and/or domain that shows in the lower window.
I have Firewall disabled and do not have any anti virus.
I also followed the procedure to move the Folder "Extension" out of the system folder Library/Safari. After I re install the Safari extension (no windows shows after I double click install) the autofill functionality works until I get out of Safari. When I re enter Safari I have the same issue.
1Password Version: 5.3 Mac App store
_Extension Version: Not Available
OS Version: 10.10.5
Sync Type: iCloud