Possible Bug with Tech Research?

[RemoWilliams]

How is this possible? I've attached a screenshot of a situation where I have researched astronomy and scientific method without having the necessary prerequisites. This is with patch 1.61.

This is a "game" where I've used worldbuilder to create a super city with all the happiness and health resources. I'm trying to figure out how a GP farm works.

I did not use any free technology bonus to research astronomy or scientific method. What happened was that I selected Industrialism from the tech chooser to get the game to automatically choose techs for me as I hit the next turn button. Eventually it started to research astronomy and I didn't think anything of it, and then scientific method, and when I looked at the tech chooser and saw I didn't have any pre-reqs, I thought, "WTH?!"

This was actually quite a bit earlier in the game than my screenshot, but you can see that I still don't have any prereqs for the techs. Weird huh? Or is there something I'm missing?

View attachment 123468

 

[MrCynical]

No bug here, this is working fine. Astronomy has no optional prerequisites, as you can see there are no arrows to it. It does however have two mandatory prerequisites (Optics and Calendar) which you do have, and so you can research it. Sci method has one mandatory prerequisite (Printing Press) which you have, and a choice of Chemistry or Astronomy as the optional prerequisite, of which you have Astronomy.

Everything's working fine here, it's just that Astronomy only has mandatory prerequisites and so has no arrows to it in the tech tree. Mandatory prerequisites are displayed as small icons in the top right corner of the tech box, whereas optional prerequisites are shown as arrows.

 

[RemoWilliams]

Well, that's stuff that I should know! Thanks.