If you haven't set any choices, then this result is exactly as supposed to be. So no strange things on that part.

I am running Windows 7, Firefox 61.0.1 64bit, so that should not matter. Check if anywhere in Virtonomics you can see this line in the console log (F12):
XioScript 14 is running! Initialise.js:5:2
If you can see that, at least we know the add-on is loaded succesfully.

Just to make sure I repeat the description of what you should see. On the unit list page, the management --> employees and management --> equipment page you should see an extra column directly to the left of the efficiency column. It starts empty, so it is difficult to see because nothing is filled in, however at the top there should be a header called "Choice". For example, my unit list has the headers "#", "City", "Subdivision", "Size", "Specialization", "Choice" and "Eff.". After creating a choice in the add-on, clicking inside the column should make the name of the choice appear.