Failed to resolve prefab modification path warning

[Ivan]

I'm seeing the following warning logged to console:

Failed to resolve prefab modification path 'events.[0].background' at step '[0]'.
UnityEngine.Debug:LogWarning(Object)
Sirenix.Serialization.PrefabModification:SetInstanceToPath(String, String[], Int32, Object, Object, Boolean&) (at C:/Users/Bjarke/Desktop/Projects/sirenix-development-framework/Sirenix Solution/Sirenix.Serialization/Utilities/PrefabModification.cs:370)
Sirenix.Serialization.PrefabModification:SetInstanceToPath(String, String[], Int32, Object, Object, Boolean&) (at C:/Users/Bjarke/Desktop/Projects/sirenix-development-framework/Sirenix Solution/Sirenix.Serialization/Utilities/PrefabModification.cs:374)
Sirenix.Serialization.PrefabModification:SetInstanceToPath(String, Object, Object) (at C:/Users/Bjarke/Desktop/Projects/sirenix-development-framework/Sirenix Solution/Sirenix.Serialization/Utilities/PrefabModification.cs:357)
Sirenix.Serialization.PrefabModification:ApplyValue(Object) (at C:/Users/Bjarke/Desktop/Projects/sirenix-development-framework/Sirenix Solution/Sirenix.Serialization/Utilities/PrefabModification.cs:90)
Sirenix.Serialization.PrefabModification:Apply(Object) (at C:/Users/Bjarke/Desktop/Projects/sirenix-development-framework/Sirenix Solution/Sirenix.Serialization/Utilities/PrefabModification.cs:53)
Sirenix.Serialization.UnitySerializationUtility:ApplyPrefabModifications(Object, List`1, List`1) (at C:/Users/Bjarke/Desktop/Projects/sirenix-development-framework/Sirenix Solution/Sirenix.Serialization/Utilities/UnitySerializationUtility.cs:1278)
Sirenix.Serialization.UnitySerializationUtility:DeserializeUnityObjectInEditor(Object, SerializationData&, DeserializationContext, Boolean) (at C:/Users/Bjarke/Desktop/Projects/sirenix-development-framework/Sirenix Solution/Sirenix.Serialization/Utilities/UnitySerializationUtility.cs:800)
Sirenix.Serialization.UnitySerializationUtility:DeserializeUnityObject(Object, SerializationData&, DeserializationContext) (at C:/Users/Bjarke/Desktop/Projects/sirenix-development-framework/Sirenix Solution/Sirenix.Serialization/Utilities/UnitySerializationUtility.cs:693)
Sirenix.OdinInspector.SerializedMonoBehaviour:UnityEngine.ISerializationCallbackReceiver.OnAfterDeserialize() (at C:/Users/Bjarke/Desktop/Projects/sirenix-development-framework/Sirenix Solution/Sirenix.Serialization/Unity Integration/SerializedMonoBehaviour.cs:25)
UnityEditor.PrefabUtility:SetPropertyModifications(Object, PropertyModification[])
Sirenix.Serialization.UnitySerializationUtility:SetUnityObjectModifications(Object, SerializationData&, Object) (at C:/Users/Bjarke/Desktop/Projects/sirenix-development-framework/Sirenix Solution/Sirenix.Serialization/Utilities/UnitySerializationUtility.cs:532)
Sirenix.Serialization.UnitySerializationUtility:SerializeUnityObject(Object, SerializationData&, SerializationContext) (at C:/Users/Bjarke/Desktop/Projects/sirenix-development-framework/Sirenix Solution/Sirenix.Serialization/Utilities/UnitySerializationUtility.cs:302)
Sirenix.OdinInspector.SerializedMonoBehaviour:UnityEngine.ISerializationCallbackReceiver.OnBeforeSerialize() (at C:/Users/Bjarke/Desktop/Projects/sirenix-development-framework/Sirenix Solution/Sirenix.Serialization/Unity Integration/SerializedMonoBehaviour.cs:31)

Steps to Repro

1. Define the following classes:

public abstract class BaseEvent {}
public class MessageEvent : BaseEvent {
    public int background;
}
public class EventManager : SerializedMonoBehaviour {
    [OdinSerialize]
    private List<BaseEvent> events;
}

2. Create an empty GameObject with an EventManager with an empty list of events.
3. Save the GameObject as a prefab.
4. Add a MessageEvent to the events property of the GameObject (not the prefab).
5. Delete the MessageEvent from the GameObject.
6. Observe logged warning.

Using Unity v5.5.0f3.

[Tor Esa Vestergaard]

Thank you for the report! We've reproduced this issue, and introduced a fix, which will be included in the next patch. The issue was that prefab modifications for elements with invalid indices were not removed when the length of a list was changed.

[Tor Esa Vestergaard]

Removing version: 0.9.0.0 (automated comment)