Oops, my fault, was trying to see if I could cheat WP by moving it to inactive before activating the new theme. Now it’s back. I really think that it the basic widget included with WP.
Well you can see it on https://www.eemsboys.nl/eb it’s the widget that is simply called Login in the widget area, so the basic widget I think.
Even though I doubt it could be atheme issue since I created both with Artisteer, what would I look for in the functions.php file then?