Q: Autofill No Longer Working On Forms?

Have you checked Safari/Preferences/Autofill to make sure all the boxes are checked? Have you checked Safari/Preferences/Passwords to make sure Auto fill is enabled?

Try going to Safari/Preferences/Extensions and disable all extensions. Quit Safari, reopen, and see if the Autofill will now load. If so, enable extensions one or two at a time until you find which extension is causing the problem.

I had the same issue, but after reentering one site's password, it saved it and autofilled it. Had to go tick the box on the top of the Safari/Preferences/Passwords to make it work. I don't recall seeing that tick box before, but then I use FireFox more often than Safari.

Had the same problem.  Disabled the 1Password extension and autofill started again.  Am contacting agilebits.