STL files not being sliced properly in Cura

Hi,
I have made my own 3D object in blender and exported it as an stl file. When I try to slice it in cura, though, it only shows the perimitor of the object.
The next thing I did was save it as gcode and printed it on an ultimaker 2+, and sure enough it just printed the perimitor.

I have tried remeshing the model in meshmixer, but unfortunately with no luck. Could it be that the dimensions are too small? its 8.56cm x 5.4cm x 0.04cm (the 0.04 is height).
The layer resolution of the ultimaker 2+ is 20 microns though, which is 0.002cm, so I don't see why the dimensions should be a problem?
Can anyone help me with this?

Thank you so much!
Attachment 9657

There is a separate setting for the first layer thickness, make sure you set that below the thickness of the card which is 0.02 at the inner section.
At that thickness the card will come out very thin and translucent like a membrane.

I think the problem is that Cura throws a hissy fit if you set the first layer at less than 150% of the layer height.

Use the scale factor in Cura to make your object 20 times as big. Once you have done that you can see the layers more easily and by reducing the scale you will get to the point where they start having 0 layers on the thin bits because Cura can't fit them in.

It is to do with your first layer height and the extreme thinness of the thing you are trying to print. When Cura makes a box yellow it still obeys the setting but is just warning you that it doesn't like it so you can set first layer to the same as the rest but it whinges.

it's just too thin :-)
it's 0.04 of a mm.

credit cards are actually around 0.8mm thick.

That's 4x 0.2mm layers.

What you are trying to do is just ridiculously thin

So I tried doing what Ralphzoontjens initially suggested, which is finding that well-hidden first-layer setting and changing it to 0.02mm. After I had set that, I switched to layer view, and then it just worked perfectly. It has now been sliced into layers, so I can see that it also includes the bottom part of the card.

Concerning the size of it, I'm aware that the file I attatched it says that its 8.56mm x 5.4mm x 0.04mm, but I don't know why it says that. When I created the object in blender, I am absolutely sure that I set it to 85.6mm x 54mm x 0.4mm. So when I import it to cura, I just scale it up to get the right size that I want
I'm gonna try to print it out tomorrow, and see how it goes. I expect that it will probably be ultra thin and very fragile, but hopefully I can work with it
Thank you so much for your help! I'm really glad you took time to answer my questions :)

well, then there's some cm vs mm confusion going on here, which probably isn't helping. The first post says the dimensions are cm.

Yeah, sorry about that. I should probably be more consitent regarding my unit of measurment, haha. The actual dimensions it's supposed to be is 8.56cm x 5.4cm x 0.04cm which is the same as 85.6mm x 54mm x 0.4mm
I'll let you know how it goes about printing it tomorrow ;)