Reproduction steps:

# Open the attached “TempFBXExportRepro” project
# Open the “SampleScene” scene
# In the Hierarchy right-click on “DoesNotExport” GameObject
# In the context menu select “Export To FBX…”

Expected result: No errors in the Console
Actual result: Export is unsuccessful, error in the Console

Reproducible with: 4.2.0, 5.0.0-pre.1 (2020.3.42f1, 2021.3.15f1, 2022.1.24f1, 2022.2.1f1, 2023.1.0a22)

Reproduced on: Windows 10

Part of the error:
KeyNotFoundException: The given key '(NaN, NaN, NaN)' was not present in the dictionary.
System.Collections.Generic.Dictionary`2[TKey,TValue].get_Item (TKey key) (at <d6232873609549b8a045fa15811a5bd3>:0)
UnityEditor.Formats.Fbx.Exporter.ModelExporter.ExportMesh (UnityEditor.Formats.Fbx.Exporter.ModelExporter+MeshInfo meshInfo, Autodesk.Fbx.FbxNode fbxNode) (at Library/PackageCache/com.unity.formats.fbx@4.1.2/Editor/FbxExporter.cs:892)