https://www.patreon.com/posts/54643780
Even after 3+ years we still have people avoiding mods that use XML Injector for whatever reason, so I'm going to explain what it is and why you need it for some of the mods out there.
XML Injector is a script mod that doesn't do anything by itself, it's sole purpose is to help other mods work in your game. This means it won't corrupt your game, won't change your game in anyway, or do anything else that you can imagine, nor is it complicated to download or install (check below for instructions, but it's the same as any other mod).
Because not everyone knows how to script, or wants to maintain a script on their own. You know how some people are good at doing math in their heads, but others aren't so they use a calculator instead, or because they don't want to do it mentally? Same thing. Or food delivery because someone doesn't want to cook, or doesn't know how? Still the same thing. Public transport? Same thing. It allows modders to make a mod without having to learn Python (entirely different system) on top of tuning, and overall is healthier for your game in the end.
So you know how when you download a mod, it mentions something along the lines of "will conflict with any mod that does such and such," or "has no known conflicts," etc.? And if you accidentally download a conflicting mod it either causes your game to act weird or one of the mods doesn't work at all? XML Injector, and other scripts, help avoid this problem by "injecting" the changes or new stuff instead of overriding those files.
For example, when a modder wants to add an interaction directly to a sim they would normally have to override a file called object_sim to do so. If every modder did this you would only be able to have one of these types of mods at a time. But thanks to XML Injector, or a mod's included scripts, you can have multiple mods that add interactions without any conflicts. So when a mod says you need XML Injector to work, they mean you need it because it injects the interactions (or other stuff in the mod) in order to work, same as if the mod already came with a script.
No, there is no modding on your end or anything else complicated. Ignore every section on that page except the one labeled "Player" as the rest is for modders. It's not a well organized page and that's why it's causing confusion for some of you, but if you just look for that section and only read that section, you'll be fine (you don't have to scroll too far to find it).
At the top of the page there is a "Download" button, click it. Ignore the second option mentioning documentation because it's for modders only.
Drop the .ts4script into your main mod folder or only one sub-folder deep, and make sure script mods are enabled in your settings. That's it, you don't need to do anything else with it. There is an optional test package included that you can run to make sure it works, but otherwise all you need to do is drop the script into the folder and you're done.
If you have any further questions or concerns, please post or message me so I can answer them. Creators, feel free to link this tutorial in your mod descriptions that use XML Injector to clear up any confusion.