Reproduction steps:
1. Open the user's attached project
2. Duplicate "Platform" prefab from the hierarchy
3. Undo, then Redo, then Undo

Expected result: Pasting Platform is reverted
Actual result: Unity crashes

Reproducible with: 2020.2.0a16, 2020.2.0f1, 2021.1.0a10
Not reproducible with: 2018.4.30f1, 2019.4.17f1, 2020.1.17f1, 2020.2.0a15

Note: In order to reproduce instead of using the prefab, you have 2 other ways:
1: MENU_ITEM -> Import Model then proceed to step 2 with your new Game Object instead of the "Platform" prefab
2: Create a new Game Object, Add a LEGO Model Asset component, press "Reimport From New File", proceed to step 2

Stack trace:
#0 0x0000010cc0363a in (anonymous namespace)::AddAssetEvent((anonymous namespace)::ChangeEventType, Object const*)
#1 0x0000010cc07334 in ObjectUndo::Restore(bool)
#2 0x0000010cc09d95 in UndoManager::Apply(std::__1::list<UndoBase*, stl_allocator<UndoBase*, (MemLabelIdentifier)122, 16> >&, bool)
#3 0x0000010cc0a2f7 in UndoManager::Undo()
#4 0x0000010cae0370 in EditMenu::Execute(MenuItem const&)
#5 0x0000010c6acff2 in MenuController::ExecuteMenuItem(MenuItem&, MenuController::ExecutionCause)
#6 0x0000010d171a00 in EditorApplication_CUSTOM_ExecuteMenuItem(ScriptingBackendNativeStringPtrOpaque*)