Reproduction steps:
1. Open the attached project “ReproProject”
2. Open the “Assets/Dematic/Fep/Test/Integration/Pouch/XOJunctionIntegration.unity” scene
3. In the Hierarchy Window, select the “P757 > xoJunction” GameObject
4. Observe the Editor’s behaviour

Expected result: Unity does not crash
Actual result: Unity crashes

Reproducible with: 1.0.0-exp.8, 1.0.11, 1.2.0-pre.12, (2022.3.22f1, 2023.2.15f1, 6000.0.0b12)

Reproducible on: Windows 11 23H2, Windows 10 (10.0.19044) 64bit (user’s)
Not reproducible on: No other environment tested

First few lines of the stack trace:

{\{0x00007ff76be2658d (Unity) TypeTreeQueries::GetFullTypeNameFromReferencedType }}
{\{0x00007ff76cd66f1e (Unity) TypeTreeQueries::WalkReferenceRegistryInstances<SerializedManagedReferencesIndex> 0x00007ff76cd706e7 (Unity) SerializedManagedReferencesIndex::LookupByRefId }}
{\{0x00007ff76cd8c82a (Unity) SerializedObject::GetManagedReferenceFromReferenceIterator }}
{{0x00007ff76cd93bd2 (Unity) SerializedProperty::HasVisibleChildren}}