Errors importing from UE to UEFN

When importing from UE to UEFN (Epic games free assets) I get all sorts of errors but the most common one is a material/texture issue… Does anyone know how I can solve them?
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@Pircolino Thank you for your report! Can you please re-post using the “New Issue” option on the Issues and Bug Reporting forums? Posts with this feature are connected directly into our development team so we can quickly get to them!

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Hi Pircolino, Welcome to the Forums.

It looks like those materials (and material functions) contain custom expressions. (In UE there are nodes you can use raw HLSL in) - Those nodes do not exist in UEFN (for stability/security reasons I imagine), so you’d need to rebuild your materials without them.

Search term if future users run into this issue: MaterialExpressionCustom