Some years ago I wrote some notes in a .txt file (plain text) on Notepad and when I opened it recently it appeared with these weird characters. I don't know at what point it turned out like that, but it could have been in-between a transition from a Windows 7 -> External Drive -> Windows 10 (current).
Another .txt files that were in the same folder as this one got like that, although the majority hadn't changed. This makes me suspect of either a conversion error between Microsoft OS or the files got corrupted.
Also, when I opened with Notepad++, this same file was written like this . When I copied it to google translate textbox, the characters with black background turned into some kind of coded matrix, so maybe it can give some kind of clue.
I already tried to decode through many ways without being successful. Maybe someone has any idea if this is a matter that can be solved through decoding to Plain Text (ASCII), or if the files are corrupted and there is no way back.