Reproducible on:

• VS version: 1.7.5
• Unity version: 2021.2.0f1
• Platforms: Windows 10 and macOS Big Sur

How to reproduce:
1. Open the user's attached project "2021.2 Beta.zip" https://editorbugs.unity3d.com/api/v1.0/attachments/4fcee54e-0cc6-435d-a547-405b0a322d05/2021.2%20Beta.zip
2. Load the "bug" Scene
3. In the Hierarchy view click on "New Script Graph"
4. In the Inspector view click on Script Machine > Edit Graph
5. In the opened Script Graph window go to Blackboard > Saved > Initial and add the new variable of any type except float.
6. Remove that variable
7. In the Hierarchy view select another GameObject
8. Observe the Console view

Expected result: Exception doesn't appear
Actual result: ArgumentOutOfRangeException appears
{code:java}
ArgumentOutOfRangeException: Index was out of range. Must be non-negative and less than the size of the collection.
Parameter name: index
System.Collections.Generic.List`1\[T].get_Item (System.Int32 index) (at <cc3d52befb6a41bd80003cf0e1c46a5e>:0)
System.Collections.ObjectModel.Collection`1\[T].System.Collections.IList.get_Item (System.Int32 index) (at <cc3d52befb6a41bd80003cf0e1c46a5e>:0)
Unity.VisualScripting.IndexMetadata.get_rawValue () (at Library/PackageCache/com.unity.visualscripting@1.7.3/Editor/VisualScripting.Core/Meta/IndexMetadata.cs:34)
Unity.VisualScripting.Metadata.get_instantiatedValue () (at Library/PackageCache/com.unity.visualscripting@1.7.3/Editor/VisualScripting.Core/Meta/Metadata.cs:281)
Unity.VisualScripting.Metadata.get_rawValueType () (at Library/PackageCache/com.unity.visualscripting@1.7.3/Editor/VisualScripting.Core/Meta/Metadata.cs:430)
Unity.VisualScripting.Metadata.get_valueType () (at Library/PackageCache/com.unity.visualscripting@1.7.3/Editor/VisualScripting.Core/Meta/Metadata.cs:446)
Unity.VisualScripting.MemberMetadata.Reflect (System.Boolean throwOnFail) (at Library/PackageCache/com.unity.visualscripting@1.7.3/Editor/VisualScripting.Core/Meta/MemberMetadata.cs:67)
Unity.VisualScripting.MemberMetadata..ctor (System.String name, System.Reflection.BindingFlags bindingFlags, Unity.VisualScripting.Metadata parent) (at Library/PackageCache/com.unity.visualscripting@1.7.3/Editor/VisualScripting.Core/Meta/MemberMetadata.cs:19)
Unity.VisualScripting.Metadata+DigMember.<.ctor>b__0_0 (Unity.VisualScripting.Metadata parent) (at Library/PackageCache/com.unity.visualscripting@1.7.3/Editor/VisualScripting.Core/Meta/Metadata.cs:1323)
Unity.VisualScripting.Metadata.Dig\[TSubpath,TMetadata] (TSubpath subpath, System.Func`2\[T,TResult] constructor, System.Boolean createInPrefab, Unity.VisualScripting.Metadata prefabInstance) (at Library/PackageCache/com.unity.visualscripting@1.7.3/Editor/VisualScripting.Core/Meta/Metadata.cs:648)
Unity.VisualScripting.Metadata.Member (System.String name, System.Reflection.BindingFlags bindingFlags) (at Library/PackageCache/com.unity.visualscripting@1.7.3/Editor/VisualScripting.Core/Meta/Metadata.cs:1440)
Unity.VisualScripting.Metadata.get_Item (System.String name) (at Library/PackageCache/com.unity.visualscripting@1.7.3/Editor/VisualScripting.Core/Meta/Metadata.cs:774)
Unity.VisualScripting.ValueInspector.get_typeMetadata () (at Library/PackageCache/com.unity.visualscripting@1.7.3/Editor/VisualScripting.Core/Inspection/Special/SystemObjectInspector.cs:17)
Unity.VisualScripting.ValueInspector.Dispose () (at Library/PackageCache/com.unity.visualscripting@1.7.3/Editor/VisualScripting.Core/Inspection/Special/SystemObjectInspector.cs:27)
Unity.VisualScripting.SystemObjectInspector.Dispose () (at Library/PackageCache/com.unity.visualscripting@1.7.3/Editor/VisualScripting.Core/Inspection/Special/SystemObjectInspector.cs:370)
Unity.VisualScripting.SingleDecoratorProvider`3\[TDecorated,TDecorator,TAttribute].Free (TDecorator decorator) (at Library/PackageCache/com.unity.visualscripting@1.7.3/Editor/VisualScripting.Core/Decorators/SingleDecoratorProvider.cs:305)
Unity.VisualScripting.SingleDecoratorProvider`3\[TDecorated,TDecorator,TAttribute].Free (System.Collections.Generic.IEnumerable`1\[T] decorators) (at Library/PackageCache/com.unity.visualscripting@1.7.3/Editor/VisualScripting.Core/Decorators/SingleDecoratorProvider.cs:317)
Unity.VisualScripting.SingleDecoratorProvider`3\[TDecorated,TDecorator,TAttribute].FreeAll () (at Library/PackageCache/com.unity.visualscripting@1.7.3/Editor/VisualScripting.Core/Decorators/SingleDecoratorProvider.cs:348)
Unity.VisualScripting.EditorApplicationUtility.OnSelectionChange () (at Library/PackageCache/com.unity.visualscripting@1.7.3/Editor/VisualScripting.Core/Utilities/EditorApplicationUtility.cs:136)
UnityEditor.Selection.Internal_CallSelectionChanged () (at /Users/bokken/buildslave/unity/build/Editor/Mono/Selection.cs:23)
{code}

Reproducible: 1.7.1 (2021.1.25f1, 2021.2.0b15), 1.7.3 (2021.2.0b15, 2022.1.0a12)
Not reproducible with: 1.6.1 (2021.1.25f1)
Could not test with: 2019.4.30f1, 2020.3.19f1 (Visual Scripting not supported)