LastPass on Safari not autofilling if auto fill is unchecked
This is an ongoing issue.


Open Preferences in Safari and select the Extensions tab
Select LastPass in the left-hand column.
Click "Uninstall" and confirm it
Go to https://lastpass.com/misc_download2.php?tab=mac#maclpmacosx
Scroll down to "LastPass for Safari" and click on "Download".
Go to your downloads folder and double-click on lastpass.safariextz.
Safari Extensions Preferences should open with a dialog box stating "Would you like to install ..."
Click on "Install from Developer" in the dialog box.
A dialog box will appear stating "Are you sure you want to install the extension LastPass..." and click on "Trust" in that dialog box.
LastPass will now show in the left-hand column of the Extensions Preferences and it will show that the version is 4.9.0.37.
A new Safari tab or window will open and at the bottom will be a "Log In" link. Click on it. This may not leave you logged in, but at this point you should be able to log in as you normally would.
You can then go to LastPass Preferences and set the preferences to your own liking.