For a correct file the error is:
==
aa.sav:1: fout: Onbekende opdracht `$FL2@'.
aa.sav:1.65: fout: Syntaxfout op `': Foutief teken U+0002 in invoer.
Translated:
aa.sav:1: error: Unknown command `$FL2@'.
aa.sav:1.65: error: Syntaxerror on `': Wrong character U+0002 in input.
==
For a file in a non-ascii path:
überhapt\bb.sav:1: fout: Onbekende opdracht `$FL2@'.
überhapt\bb.sav:1.65: fout: Syntaxfout op `': Foutief teken U+0002 in invoer.
however on the screen I see not "überhapt" but "3berhapt". In the redirected output file, I see the text above.....