Tech scramble?

[Nod2003]

has anyone encountered a bug where your tech gets scrambled? I was trying a high population game on earth, and in 1887, I got a science message to pick a tech. One of the choices was alphabet. An odd option as I had already discovered railroads and was happily laying track through India. I looked at my science advisor on the next turn, and I have lost many techs, including alphabet, writing, the republic and railroad, but have inexplicably gained some techs such as computers, nuclear fission, and metallurgy. The tech changes described are a sample, not all inclusive. Any ideas what happened, and short of a save reload, how to fix it?

 

[Posidonius]

An overflow somewhere has pushed a byte or two of data in your save-file forward. Play around with it. Might mean that you can now build a Wonder which was previously destroyed. Again, if you're trying for max population, Earth is not where you want to be. It's got 176 deserts, 31 mountains, 95 snow, and 65 hills.

 

[Nod2003]

Yeah I realize earth isn’t best for pop. I was using it to hone technique on a known nap before going LWWY

 

[Posidonius]

Yeah I realize earth isn’t best for pop. I was using it to hone technique on a known nap before going LWWY

Warm and Wet are obvious, because snow and deserts are 0-food squares. The key is the Young planet. Young means larger contiguous blotches of the same terrain type. Sometimes you'll get huge mountain ranges, retire the game and move on. But once in a while, the large blotches are vast river systems. Remember that 327 million people in 128 cities is only about 2.5 million per city. That's 22 to 23 citizens. With RR and irr on a grassland, that's 4 food from one square and you only need 11 of those to get up to 22 citz.