When I tried to install k3b it failed complaining about a setting in neptune-settings-plasma5-profile (2.16) that couldn't be overwritten. I uninstalled the neptune-settings-xxxxx and then k3b installed fine. I don't know what other settings that might have been affected by doing this so I didn't try to reinstall the neptune settings 2.16 again. I didn't notice anything bad as a result.