Thank you, that worked. Excellent support, you guys rock.

Attached, I think...

Okay, I figured out how to use the console, I think. Ran the script. Didn't seem to have any effect. Now to figure out how to post the save...

I have never installed any mods.

I don't understand where/how I should run /c game.player.force.reset_technology_effects()

I'm working in creative mode, with the option to craft infinite items. I've used the same map for many months, starting in version 0.16.XX. I'm sure the fast inserters were on the menu before, but today I went to craft them and they're not in the list anymore. I don't know when or how it happened ...