[0.15.9] Sulfur is not a prereq of Adv Elec 2

[taralx]

Advanced Electronics 2 requires Sulfuric Acid, but does not have Sulfur as a direct or indirect prerequisite. It's not a big deal, but it probably should have it -- I was very confused when I couldn't make the acid!

[Klonan]

Advanced Electronics 2 requires Sulfuric Acid, but does not have Sulfur as a direct or indirect prerequisite. It's not a big deal, but it probably should have it -- I was very confused when I couldn't make the acid!

Thanks for the report,

We don't explicitely list all the required prerequisite technologies, as it would just clutter the GUI, and not add much,
This means some technologies/recipes are unlockable, but not able to be produced at that time

But in the end it isn't a bug, there are many of these cases