Unity throws console errors trying to view fbx animation import tab

my Unity version is 2019.3.0f6
Import attached files and go to animation tab.
Instead of animation clips editing interface it shows only two top checkers and throws errors in console

NullReferenceException: Object reference not set to an instance of an object
UnityEditor.ModelImporterClipEditor.FindNextAvailableName (System.String baseName) (at <6f28216fea9f453abf2e05b770ed3ee4>:0)
UnityEditor.ModelImporterClipEditor.MakeUniqueClipName (System.String name) (at <6f28216fea9f453abf2e05b770ed3ee4>:0)
UnityEditor.ModelImporterClipEditor.AddClip (UnityEditor.TakeInfo takeInfo) (at <6f28216fea9f453abf2e05b770ed3ee4>:0)
UnityEditor.ModelImporterClipEditor.SetupDefaultClips () (at <6f28216fea9f453abf2e05b770ed3ee4>:0)
UnityEditor.ModelImporterClipEditor.OnEnable () (at <6f28216fea9f453abf2e05b770ed3ee4>:0)
UnityEditor.AssetImporterTabbedEditor.OnEnable () (at <6f28216fea9f453abf2e05b770ed3ee4>:0)
UnityEditor.ModelImporterEditor.OnEnable () (at <6f28216fea9f453abf2e05b770ed3ee4>:0)

it seems to be editor UI error.
This happens in fresh project too.
This do not happen in previos unity version.
One article on GitHub suggest that this happends because of version specific code in UnityAPIWrapper, i dont know what does that even means.

I am having the same issue. It looks like an error in unity with the import. i rolled back unity to an older version (2019.2.4f1) and the import worked perfectly. i also imported the .fbx into unreal engine just to test it and it worked there as well.

i have tried numerous workarounds and have had no success.

Good luck.