Incorrect Vertex normals of mesh in custom version of UE4

As you can see in the screenshot. The normals are fk’ed. The import setting are set to default in custom UE4.27. If I import mesh from blender, maya, different version or project of blender/maya I get this same result. If I export this same mesh as fbx from unreal and I reimport it back then I get this problem. If I import in a different new empty project of same engine, I get the same problem (I will write this sentence as “same P” now). If I export the fbx from different version of unreal and import it in custom version, same P. My colleagues sent me their fbx from their blender and unreal, same P. Importing in different version of unreal does not result in same probem. If I import whatever they way into standard UE4.27 then it imports correctly. If I send the same mesh to my colleagues then in their system it imports correctly both in standard and custom ue4.

So we basically narrowed down that it’s engine problem and specific to me only. How do I fix this?

  1. Verify Import Settings: Double-check the import settings for your meshes in Unreal Engine. Ensure that the options related to normals, such as smoothing groups or vertex normals, are configured correctly. Experiment with different import settings to see if any adjustments resolve the issue.

  2. Check Normals in 3D Modeling Software: Before exporting your meshes from Blender or Maya, examine the normals to confirm that they are correct. Make sure that the normals are facing outward and are consistent across the entire mesh. You can use the “Normals” display mode or tools in your 3D modeling software to visualize and edit normals if necessary.

  3. Update Graphics Drivers: Ensure that your graphics drivers are up to date. Outdated or incompatible graphics drivers can sometimes cause rendering issues in Unreal Engine. Visit the website of your graphics card manufacturer to download and install the latest drivers for your GPU.

  4. Reset Unreal Engine Preferences: Try resetting the preferences and settings of your custom version of Unreal Engine. Corrupted or misconfigured settings could be causing the abnormal behavior. You can reset the preferences by deleting or renaming the “Saved” and “Config” folders located in your Unreal Engine project directory.

  5. Reinstall Unreal Engine: If the issue persists after trying the above steps, consider reinstalling your custom version of Unreal Engine. Make sure to completely uninstall the existing installation and then reinstall the engine from scratch. This can help resolve any underlying issues with the engine installation.

  6. Contact Unreal Engine Support: If you’re still unable to resolve the problem on your own, consider reaching out to Unreal Engine support for assistance. Provide detailed information about the issue, including your system specifications, steps to reproduce the problem, and any relevant files or screenshots. They may be able to offer further guidance or insights into resolving the issue.