How to reproduce:

1. Create new project
2. Create any GameObject in Hierarchy window
3. Open Windows > Animation > Animation
4. Create New Animation and Save
5. Open Windows > Animation > Animator (important)
6. Drag/Drop new Animation into Animator Controller window
7. Right click on Any State Node
8. Make transition to the added Animation
9. Click on the Transition Arrow
10. Observe the error in the Console window

Expected results: No errors
Actual results: Multiple errors are thrown in the Console window
{noformat}
NullReferenceException: Object reference not set to an instance of an object
UnityEditor.Graphs.AnimationStateMachine.AnimatorStateTransitionInspector.DoErrorAndWarning () (at <b33671bcae5847dba5182ede845a38ef>:0)
UnityEditor.Graphs.AnimationStateMachine.AnimatorTransitionInspectorBase.OnInspectorGUI () (at <b33671bcae5847dba5182ede845a38ef>:0)
UnityEditor.UIElements.InspectorElement+<>c__DisplayClass71_0.<CreateIMGUIInspectorFromEditor>b__0 () (at <808fed1db5d34c2a9416f9a4a396d0d5>:0)
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr, Boolean&){noformat}
 

Reproducible on: 2022.1.0a6, 2022.1.8f1, 2022.2.0a18, 2023.1.0a2
Not reproducible on: 2022.1.0a5

Notes:
- Tested on : Win11, MacOS Silicon (Monterey 12.3.1)
- Moving mouse cursor around in the Inspector window throws more errors.