The attached file probably comes from a Mac (linebreak is
LF). Apart from a few numbers, it consists exclusively of U+003F QUESION MARK and some spaces. As @gabix pointed out, it is neither an .odt not a .docx document. It was probably a plain text one but it underwent encoding conversion to ASCII, losing all non-ASCII characters. There is some math inside but everything is damaged beyond repair.
Put your hand on the original file and save it as an .odt document. Avoid errors when you get it.
Nothing else can be done.
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