Hi @sharpeye1713 I don't know which one that is exactly, as there are many out there. Sounds to me like you have just chosen one, out of a 'pose pack'? A picture of your pose folder would help here..
If you mean, you can't add other sims without it 'looking' normal, that's because gallery (pose) mods are made for 1, 2 and more people.. and you can also only add a certain number of them.. For one sim, there is usually about 6 to cycle through. Pose(s) in these packs, should be named something like xyz1,xyz2,xyz3.. to an effect (it helps to remember which ones which when deleting or replacing some as well) There simply can't be 2 number 1 poses etc.
If it's broken, just remove it, I have about 6 of each, for 'male', 'female', and I think a 'group of 3' one.. but you can't have say 'female 1' x 2 (from different people, js, for future reference.. most will include a txt file or a guide) poses are usually numbered consecutively in this way, to ensure that there are no conflicts, so it has to be 1 - 6.
There are a few you can find on Tumblr, there's simslover14333, Blewis50.. and I'm sure a lot more, but those 2 come up under "recent", which I always prefer to use.. and make sure things are current.
Let me know how it goes..
Sasha
nb: just in case, also ensure you have a 'gallery pose pack' and not a game play pose, (expecting it to work in the Gallery) as they won't work in the gallery, some are misleading in the 'look' but aren't gallery poses is all