Found typo errors in mk 2, 3 and 4.

<FlavorType>FLAVOR_DEFENSEL</FlavorType>

Should be

<FlavorType>FLAVOR_DEFENSE</FlavorType>

You definitely shouldn't be able to build the missiles immediately. What DLC/mods are you using?

The mod works nice and i love it but its just that you can build the normal missiles immedeatly. Like from the beginning. I dont know if it is intendet to one-shot everything in the beginning but yeah just wanted to let ya know

Okay let me know if you find anything, it'll be interesting to learn what's causing it. Sorry you're having difficulties using the mod.

No, I am not. I couldn't even begin to speculate what may be going on, as this is something I have not encountered before. I can continue to test around with things on my end (as it seems like it may be an issue on my end), it just may take some time.

I tested using the G&K and BnW DLC, with multiple mods loaded, but I don't see any issue. Are you playing with any mods that change the Tech Tree?

It happens with any mod loaded.

Is there a specific mod that causes it to glitch, or is it if any mod is loaded after it?

If you by chance are still playing Civ.: the mod seems to stop working whenever I load in a mod after it. (It works fine when I first load it.) When it glitches every version after the first (guided missile) is removed from the game. Yet, the [mk 1] is still in the game; ie. the altered version of the guided missile despite mk 2, 3, and 4 being removed.

That would be boring.

fun mod

I realize my mod is not historically accurate. The goal of this mod is not about history, but gameplay.

Modern era is WWI level tech. Guided missiles make no sense in that era. The Atomic era is WWII. There were rockets in WWII, but they were barely guided.