Is it a bug? Is it misused?

[codesafe]

Hi.
Using your AtlasImage, I created two AtlasImages in samplescene.
Then, the following error is occurring. How should I fix it? Maybe it's a bug?

Could not extract GUID in text file Assets/Scenes/SampleScene.unity at line 404.
Could not extract GUID in text file Assets/Scenes/SampleScene.unity at line 864.
Broken text PPtr. GUID 00000000000000000000000000000000 fileID 2 is invalid!
Broken text PPtr. GUID 00000000000000000000000000000000 fileID 2 is invalid!

I use Unity 2019.4.14f.