This is the code:

 

NBTTagCompound stackTagCompound = new NBTTagCompound();

NBTTagList list = (NBTTagList) stackTagCompound.getTag("String"); // Works
NBTTagList list = stackTagCompoung.getTagList("String", Constants.NBT.TAG_LIST); // Does not work.

 

And yes, i know i didn't give the stackTagCompound anything to pull from, but this is just example code.

i have already figured out the workaround, but i wanted to let the community know, and ask if i am doing anything wrong. Sorry if i am, but it was really annoying to deal with that.

Yes, you are, unless you are storing a list of NBTTagLists, you should not be using Constants.NBT.TAG_LIST. Use whatever type of NBTBase is stored in your list, for example when storing a list of NBTTagCompound such as found in inventories:

public void readFromNBT(NBTTagCompound compound) {
super.readFromNBT(compound);
NBTTagList items = compound.getTagList("Items", Constants.NBT.TAG_COMPOUND);
for (int i = 0; i < items.tagCount(); ++i) {
NBTTagCompound item = (NBTTagCompound) items.getCompoundTagAt(i);
// etc.
}
}

thank you, i thought that the constant was for getting the nbttag, and not for the type of it. sorry i didn't realize that.