Mods don't work

There are many reasons a mod might not work, including:

• You need to own certain packs for that mod (see the mod's instructions page)
• You need to download other mods for it to work (see its instructions page)
• It conflicts with other mods you have (sometimes this is covered on an instructions page)
• It's broken (see Previously Broken and the current Broken/Updated Mods & CC)
• It's a script mod and you installed it too deep in your folders
• It's a mod that requires you to not change its name or its folder's name 
• It's a script mod but you didn't enable script mods in your Options. See Mod/CC Issues master post about if that setting keeps turning itself off.
• You're accidentally using the wrong folder. See How to Use Mods and CC for more on that.