Are you using cycles?

I am, but i guess i understand the problem better now. The custom texture that i worked with is a png and blender works with pure vector based graphics. If that is indeed the issue, i guess the only solution is using the preset models.

Ok, so I do this all the time. If you want to modify or use a custom texture within Blender, then the easiest thing to do is to start with a "donor" part from Mecabricks. Then go into the decorations group inside the shader editor and swap out the MB image with your own. That's the very basics of it. Blender requires a raster image (bitmap, png, jpg) for texture images. You can't texture with SVGs, so that's not the issue.

There is one big issue working with donor parts though. Over time, Scrubs has periodically updated parts. There was a major revision to the textures where they used to use solid backgrounds and now they use transparent backgrounds. If you try to upload a transparent background image to a part that uses the legacy system, things either get weird or can totally break. It's hard to diagnose the issue based on the limited information you've given so far though.

Here's a few questions:

1. What part are you trying to modify?
2. What tutorial did you follow?
3. Are the non-custom textures working just fine as well?
4. Can you post a screenshot of Blender with the entire 3d viewport and the node setup for the texture?
5. Can you make the model public?

At first sorry for the late response,
I am trying to modify the upper body part of the model, so the corso.
I followed the tutorials ''How to create Custom prints on Mecabricks'' and ''How to Take Your Mecabricks Renders to the next level with Blender''
The non-custom texture work fine.
How to post screenshots, and how to make models public?

Hi Bryan-

This is the tutorial that I wrote... it works for me:
https://www.mecabricks.com/en/forum/topic/2925

If that doesn't fix the problem, seeing what you're working with is worth its weight in gold.

If you can post the part number (3814dxxx) that will help... but seeing what is going on in blender will be very useful:

Use this thread for how to post a screenshot:
https://www.mecabricks.com/en/forum/topic/2714/1

Here is how to make a model public:

1. Click on your user name in the top right corner.
2. Click on the Library button in the blue bar (NOT the link at the top of the page)
3. Double click your model.
4. Toggle the checkbox on next to "Open to the public"
5. Click Save

Thanks again for replying so fast,
I made a screenshot of whats happening in blender
https://i.imgur.com/0Xuq9vO.png

I think i also made the model public, so you can take a look at it.

I hope this makes it clear what my problem is.

Ok, easy fix... you have two torsos sitting on top of each other. So they are fighting with each other and you're getting triangles all over the print. Delete, hide, or move the one that you don't want. That will solve your problem. You can do this in blender or mecabricks.

It worked! Didn't realise it was that easy to fix, thank you so much for your help!

Glad it worked!