Bug Reorderable List broken for me in 2020.2.6+

Hi,

I have been using IMGUI Reorderable lists in my plugin since 2018.4 and they have worked fine until now.

In Unity versions 2020.2.6+ they have suddenly stopped working as the serializedObject is being disposed for some reason.



I get this error pretty much anytime I modify the list by adding a new element or trying to delete an element. Oddly it doesn't occur when re-ordering elements. It also triggers on ReorderableList.DoLayoutList() immediately after deleting the element.

Is anyone else having this issue? Does anyone have a quick fix? The fact that it has randomly started occurring in a Unity minor version makes me think it is an introduced bug. Any help is greatly appreciated.

 

I'm seeing something similar in 2020.2.6+ - my Editor classes are being disposed and recreated every few seconds, seriously messing up the state of my objects.

 

I found a workaround for my purposes, not sure if this will help anyone else but I'll post it here just in case.

For my use case I create assets and add them as sub assets to a parent to help with serialization. After adding them to the object I re-import the asset to make sure it shows up properly. Originally (back in 2018.4) I called AssetDatabase.Refresh() but this was too slowed down the editor a lot at the time. However, in 2020.2+ it doesn't seem to be that slow. I replaced my re-imports with AssetDatabase.Refresh and this problem goes away for me.

Here's an example:

Code (CSharp):

1.  
2.     AssetDatabase.AddObjectToAsset(newComposite, m_data);
3.     newComposite.hideFlags = m_spHideSubAssets.boolValue ? HideFlags.HideInHierarchy : HideFlags.None;
4.  
5. #if UNITY_2020_2_OR_NEWER
6.     AssetDatabase.Refresh();
7. #else
8.     AssetDatabase.ImportAsset(AssetDatabase.GetAssetPath(newComposite));
9. #endif