Reimport Material Conflict (FBX Reimport)


Version 4.20 seems to have some odd ideas of reimporting FBX-Meshes. It always opens this “Reimport Materials Conflict Resolution”-thingy nevertheless this original material is there or not. It goes through this dialogue for every single part of the mesh which makes it literally unusable for any mesh modifications without a complete new Import (which also means new material assignments and so on).

There is also no real instruction on how to use this thing? It says to Right click, but only offers “Clear all” and the “Material” - what does that do? And why does it for every single mesh… as said - unusable for FBX.

Finally the Editor crashes after 20-something mesh parts.

What you need to do is resolve every conflict shown non white on the left side of that dialogue. The reason you are getting this conflict is the sections names in unreal don’t match the material names in the fbx you are reimporting. This usually occurs if you rename the material assigned to a mesh in your content creation tool like Maya. If you hover your mouse over the section names in ue4 the tool tip will show you the material name used to create the section the first time you imported the mesh.

To resolve the conflicts “make them white on the left side” , right click the new material section name on the right side and pick the ue4 section that you want use to import into the right side. Once all conflicts are white click Done.

This will Work exactly like you want. It will also update the asset to the new material section names so another reimport will not have conflicts. Sorry if this was as clear as mud. This dialog confused me as well and I got similar results as you until i understood it.

I am with OP on this. Last time i imported static mesh to UE was in ~4.17-18 and importing was without issues. Now i have to deal with this dialog that offers no explanation of its purpose. I cannot find any official document on this ‘feature’. I don’t name my material in 3ds max, i just assign ID in multisubmaterial. Even if i don’t change IDs just apply blank material to the mesh, the dialog still shows up. AND, it adds new material element to the asset. I found i have simple meshes that have only 1-3 material ID in 3ds Max and have 8 material elements in UE. How is this helping, how do i turn this off?

Thanks for responding Dan but can you go into more detail about the tool itself? What is color key on the bottom- like "auto matched? Also when I right clic the “reimport asset materials” > “unamed” I have two choices in the drop down. “World Grid Material” and “World Grid Material” (excactly the same but choosing one keeps it green and “unamed”. Choosing the other makes it green and changes it to “unnamed match with [1]WorldGridMaterial”

I have been encountering this issue a lot lately, sometimes I get luck and it fixes it self and other times it is constantly changing material slots on me. My solution I have found is simple but effective, reimport your model with one material ID on it, delete the extra material slots, then reimport again with old material ID’s. This should work.

This! This dialog windows is truly un-intuitive with very little practical info about how it works. Plus, some of us don’t use Maya (but 3ds Max in my case). There are probably users that can benefit from this dialog and what it offers, but for me, not once it solved anything. It always mangled order of the materials, or somehow fuse them together. Simplest solution i am using now is to use UE 4.17 and when the asset is done, import it to current version of UE.

First i noticed this in UE 4.14, i wrote bug report about it and it was fixed in 4.15. But, in later versions of UE, this dialog showed up and no matter what i try, it always gets it wrong.

Bug report can be found here:
I also submitted bug report UE-65797 that has is related to this. Short video describing problem can be seen here: Unreal editor mesh import problem. - YouTube

It doesn’t matter even if you don’t change any material ie like in my case all i did was update a model an this window 1 takes for ever to load and 2nd you can event clear it out all at once its one at a time this is so not efficient. If i was on a job it would be over as most of time time would be sitting here looking a this screen all day.

How do you avoid this issue?

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Man I struggle with this in Unreal Engine 5 (5.0.3 to be precise!)
It asks me this for every object, with 20 seconds of calculations in between. I have approx 200 objects. So this would take a full hour. Totally un-useable workflow!

Seem to be having this issue but in a very weird way. I have a datatable thats loading in different types of meshes with different materials etc but now a lot of them dont spawn the material properly.

I imported two meshes (no materials) and this popped up, clicked done and now whenever I play, the materials of other meshes get messed up, even though it has nothing to do with the meshes I imported.


the material above is being put on it when it should be this:


In the mesh editor, it looks completely fine, nothing wrong with the materials, only when play is pressed does it not spawn the materials correctly.

When I look at reference viewer of that material thats on it, the MI_ProcGrid (which is an engine landscape material it seems), it links into the base mesh that is used as a placeholder mesh if one cant be found in the datatable of meshes. It also links into all the maps.

Its definitely an engine problem as I have swapped branches in my source control and that doesnt change anything, it happens on every branch, even really old ones.

I have tried redownloading my repo, and updated the engine (im using 5.0.3) and verified the engine files. Nothing has helped. Next thing to try is to uninstall and reinstall the engine but I really dont want to as that will take ages and I have other projects that im working on.

Anyone know why its replacing the materials with this ProcGrid one? Im baffled at this point ;(