Nullref when serializing asset on Unity 2022

[laicasaane]

Unity 2022.3.14 SpriteDicing 1.10.0

I'm receiving this exception when trying tpo build the atlas.

Failed to build diced sprite atlas. System.ArgumentNullException: Value cannot be null.
Parameter name: _unity_self
  at (wrapper managed-to-native) UnityEditor.SerializedObject.ApplyModifiedProperties(UnityEditor.SerializedObject)
  at SpriteDicing.Editors.AtlasBuilder.<PackTextures>g__SaveAtlasTextures|8_2 (System.Collections.Generic.IReadOnlyList`1[T] textures) [0x0003d] in D:\Projects\SpriteDicing\Assets\SpriteDicing\Editor\Editors\AtlasBuilder.cs:106 
  at SpriteDicing.Editors.AtlasBuilder.PackTextures (System.Collections.Generic.IReadOnlyList`1[T] dicedTextures) [0x00068] in D:\Projects\SpriteDicing\Assets\SpriteDicing\Editor\Editors\AtlasBuilder.cs:77 
  at SpriteDicing.Editors.AtlasBuilder.Build () [0x0000f] in D:\Projects\SpriteDicing\Assets\SpriteDicing\Editor\Editors\AtlasBuilder.cs:32 
UnityEngine.Debug:LogError (object)
SpriteDicing.Editors.AtlasBuilder:Build () (at Assets/SpriteDicing/Editor/Editors/AtlasBuilder.cs:38)
SpriteDicing.Editors.DicedSpriteAtlasEditor:DrawInputFolderGUI () (at Assets/SpriteDicing/Editor/Editors/DicedSpriteAtlasEditor.cs:142)
SpriteDicing.Editors.DicedSpriteAtlasEditor:OnInspectorGUI () (at Assets/SpriteDicing/Editor/Editors/DicedSpriteAtlasEditor.cs:43)
UnityEngine.GUIUtility:ProcessEvent (int,intptr,bool&)

[elringus]

Probably a Unity regression as it's working fine on 2019.4.

[github-actions[bot]]

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[SJT1988]

I am also getting this error Unity 2022.3.16f1

[elringus]

Unity seem to dispose/invalidate atlas asset editor before the build is complete (and even before the draw is finished):

https://github.com/elringus/sprite-dicing/blob/365db9c695297fc2b35296cadbea21606d4401dd/Assets/SpriteDicing/Editor/Editors/DicedSpriteAtlasEditor.cs#L141-L143

— after Build() is invoked, editor's OnDisable() gets called (which indicates Unity decides to dispose the editor and serializedAsset instance with it) before control flow exits the method. This is most likely a regression on the Unity side, as the behavior is weird and didn't happen in previous Unity releases.

I'm not using 2022 myself; would appreciate if someone can send a bug report to Unity and/or have an idea of a workaround/temp fix, which doesn't require significant changes on our side.

[elringus]

I've traced it down to AssetDatabase.SaveAssets() call:

https://github.com/elringus/sprite-dicing/blob/365db9c695297fc2b35296cadbea21606d4401dd/Assets/SpriteDicing/Editor/Editors/DicedSpriteSerializer.cs#L81

Seems like invoking those causes Unity to dispose the editor. After removing all the "SaveAssets" in all the editors (except the last one at the end of build), it seems to work fine, until you change any property, at which point it fails again, but works when repeated. As a temp workaround (until the bug is fixed on the Unity side), try removing the save calls and build twice after changing atlas properties.