https://sims4studio.com/thread/19499/make-custom-loading-screen

In this tutorial, I will show you how to make your own loading screen for the sims 4!

So first we open sims 4 studio and create a new empty package file:

Then we go to tools --> game file cruiser

paste this "432D1D2ADDFFC6D8" in the "instance" form, then click on "all", select the added entry, and click on "export", export the file as a binary, the name doesn't matter

Now we will need an SWF decompiler, i will be using JPEXS decompiler, change the filetype from .binary to .gfx

open the file with JPEXS decompiler, if you get asked this, click "no to all"

Click on shapes, and right-click on the blue texture, and click export selection

export it as a png, now you can edit it as you want but do not change the resolution

after you are done editing right-click the blue texture and click on replace, browse to your texture and click open, after that click on save

close the decompiler and change the extension of the file from .gfx back to .binary, then get back to sims 4 studio and click on "add", where it says type select "ScaleFormGFXResurce" and where it says "instance" paste this "432D1D2ADDFFC6D8" click on ok