Hi,
the file seams to be corrupt. If i read the src correctly it happens when godot reads the initial tag to get the type of file it is reading. But parsing the first tag fails.
First tag of a scene must look like … [gd_scene load_steps=5 format=2]
but can have different values.
Have you edit it with a texteditor? Maybe a BOM header has been added (first invisble byte of the file).
indeed, the scene file was corrupt. After looking inside the file, the file is mysteriously empty, but never have i edited it