Illegal Sequence

An illegal multibyte sequence was found in the input. This usually means that you have the wrong charactor encoding, for instance the MicrosoftCorporation version of latin-1 (aka iso_8859_1(7)) (which has it's own stuff like "smart quotes" in the reserved bytes) instead of the real latin (or perhaps utf8(7)).

Try changing which encoding you expect and try again.

For example if you are using the iconv(1) command or library (note that iconv doesn't actually raise that error, but this demonstrates the problem)
$ echo -e "\0777 is an invalid utf-8 byte" > myfile $ iconv -f utf-8 -t iso-8859-1 myfile iconv: illegal input sequence at position 0 $