I checked, and the Godot folder is 16-bit and is compatible with Godot animation toolset. But the 32-bit and 48-bit assets are not compatible. Can you update the 32-bit and 48-bit animation tilesets to be single row or single column for each animation?
They seem to be 16-bit. I found the files outside the Godot folder for 32 and 48, but the animations don't line up (they are in 2 rows instead of 1). Same for all the themes. Let me try downloading the latest copy to see if things have changed.