Hoping to pick some experienced modders' brains!

I've created by first ever custom mod for the Sims 4 - I'm a huge fan of Sons of Anarchy so I decided to try and make a kutte for one of the characters. The mod itself seems to be fine but it turns the rest of the sim (including hair, trousers, skin) white and I have no idea why!

I've searched help forums but nothing like this has come up - I've seen a lot of white and red square stuff but not pure white. I've included a picture to this post so hopefully that helps.

Any help or advice would be very much appreciated!!

Can you also share your package file please?
At a guess I would say that you flattened your image before importing? If so that will remove all of the transparent bits of the texture which is why it is covering the rest of the Sim in white.

It doesn't seem to want to let me upload the package itself here (it's not included in the extensions) - if there is a way, very happy to share it. I did flatten the layers down in Adobe so could that be the cause?

You have to put the package in a zip file. 7zip is a good tool for that.

Yes, when you flattened the image you eliminated the alpha channel which defines where the image is transparent. Depending on the image editor, flattening will leave the areas that were transparent white, which then makes the whole sim white.

Worked like a charm!! Thank you both for being so helpful