Rated 4 out of 5 stars
Using this on archlinux with KDE (current 5.26) and firefox (current 49.0.1-1). Since recently (I suppose the update from KDE 5.25) login forms are not autofilled anymore. firefox' password manager shows the passwords from the wallet are imported, as stdout confirms (lots of "Converted key:" lines).
Also, please provide a proper error reporting channel!