Steps to reproduce:

1. Create a new unity project
2. Open Build Profile Window
3. Add a new Build Profile (Library/BuildProfileContext.asset should be created)
4. Close the Editor
5. Open Library/BuildProfileContext.asset and change the m_Script field from the valid built in reference to any invalid one, e.g. 
6. m_Script: \{fileID: 11500000, guid: aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa, type: 3}
7. Save the file and reopen the Editor
8. Open Window > Build Profiles

Actual results: Console errors and classic platforms list and user-created profiles list are both empty

Expected results: The Build Profiles window should open normally with all platforms and profiles present.

Reproducible with versions: 6000.0.60f1, 6000.6.0a1

Tested on (OS): MacOS
{code:java}
BuildProfileContext asset exists but could not be loaded.
UnityEditor.EditorApplication:Internal_CallGlobalEventHandler () (at /Users/bokken/build/output/unity/unity/Editor/Mono/EditorApplication.cs:570)

NullReferenceException: Object reference not set to an instance of an object
UnityEditor.Build.Profile.BuildProfileContext.CreateOrLoad () (at /Users/bokken/build/output/unity/unity/Editor/Mono/BuildProfile/BuildProfileContext.cs:746)
UnityEditor.Build.Profile.BuildProfileContext.get_instance () (at /Users/bokken/build/output/unity/unity/Editor/Mono/BuildProfile/BuildProfileContext.cs:206)
UnityEditor.Build.Profile.Handlers.BuildProfileDataSource..ctor (UnityEditor.Build.Profile.BuildProfileWindow window) (at /Users/bokken/build/output/unity/unity/Modules/BuildProfileEditor/Handlers/BuildProfileDataSource.cs:20)
UnityEditor.Build.Profile.BuildProfileWindow.CreateGUI () (at /Users/bokken/build/output/unity/unity/Modules/BuildProfileEditor/BuildProfileWindow.cs:170)
System.Reflection.RuntimeMethodInfo.Invoke (System.Object obj, System.Reflection.BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) (at <3eb0070ec3184acfa9cdfc9616bb21ab>:0)
Rethrow as TargetInvocationException: Exception has been thrown by the target of an invocation.
System.Reflection.RuntimeMethodInfo.Invoke (System.Object obj, System.Reflection.BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) (at <3eb0070ec3184acfa9cdfc9616bb21ab>:0)
System.Reflection.MethodBase.Invoke (System.Object obj, System.Object[] parameters) (at <3eb0070ec3184acfa9cdfc9616bb21ab>:0)
UnityEditor.UIElements.DefaultEditorWindowBackend.Invoke (System.String methodName) (at /Users/bokken/build/output/unity/unity/Modules/UIElementsEditor/WindowBackends/DefaultEditorWindowBackend.cs:387)
UnityEditor.EditorApplication:Internal_CallGlobalEventHandler() (at /Users/bokken/build/output/unity/unity/Editor/Mono/EditorApplication.cs:570)
{code}
 

Notes:

• Workaround: delete Library/BuildProfileContext.asset and reopen the Editor.
• I could not reproduce organically. The repro above manually corrupts the asset file to trigger the code path. But there are multiple reports of this occurring naturally in our Discussions forums
• [https://discussions.unity.com/t/my-build-profile-no-longer-shows-up/1619616]