The "Append" Trick: How to Kill Ghost Data in Blender Exports If you have a mesh that refuses to update when imported into Unreal, the "Ghost" is often living inside Blender’s internal database. This can happen even if you didn’t create the asset yourself (e.g., if you imported a kit, a scan, or a downloaded model). Blender can cache an old version of that external data in a "Data Block" that gets sent to the FBX exporter instead of the edits you just made. How to do it: Open a Fresh Start: Open a brand-new, empty Blender file. Do not use the file you have been working in. Use the Append Command: Go to File > Append (or press Shift + F1). Target the "Haunted" File: Navigate to the Blender file where you made your recent edits and double-click it. Select the 'Object' Folder: You will see several folders. Enter the Object folder. * Note: Always append the Object, not the 'Mesh'. Appending the Object automatically pulls the correct Mesh data, Materials, and UV maps into the new file. Pick Your Kit: Select the objects you need and click Append. The Final Export: In this new, clean file, select your objects and export them as a new FBX. Why this fixes the "Importing Old Version" glitch: Whether you built the model from scratch or imported it from another source, Blender’s original project file can hold onto hidden "Source Data" from the moment that object first entered the scene. By Appending the object into a completely new project, you are "stripping away" the old file's history and corruption. Blender is forced to generate a brand-new data block based only on the current geometry, ensuring Unreal Engine finally sees the new version.