Custom 3D CAS background doesn't appear in game

Sooo...I'm this type of person who always first tries to solve the problem by themselves BUT this time I'm completly clueless on what went wrong.This time (I am beginner in blender but I understand basics of making sims 4 cc) I was trying to do the remesh of the cutesheepmie.tumblr.com/post/714056492687491072/acgn-casbackground-cinnamoroll   CAS background. I was following the cloudcat.tumblr.com/post/691150427988918272/hey-cloudcat-im-also-working-on-my-own-cas tutourial. Yes, i can "create 3D mesh" and "import 3D mesh" everything till now works. BUT as soon as I try to go in the game with my newly created package file, my CAS bg package just doesn't appear. Its plain old base game CAS background.

I tried:
- lowering poly count
- triangulating mesh
- deleting all mesh groups (as said in the tutourial)
- doing comparison on my file and 3d backgrounds from other creators in the Sims 4 studio (it seems that everything is right with mine so i just dont know anymore.)
- deleting cache files of sims 4
- using my mesh on other 3D cas backgrounds

Well I just dont know what to do anymore. 
In case anyone knows how to fix it, or has any sugestions on what can I do ,I will get you folder with Blend file of original background and Blend file of mine, also the package of my file that works in sims4studio but doesnt appear in the game,and the orginal.I will be very thankful for any help.

(yeah the mesh in mine can be kind of low poly because I just tried lowering the poly count but I will fix that later, same as broken textures.I just wanted to test it if it works and it doesnt lol)


Here's the folder: 
mega.nz/folder/gdcWQRQL#QnyeTebHkTvikg7OGGHbag