UnicodeDecodeError: 'utf8' codec can't decode byte 0x9c

Question

I have a socket server that is supposed to receive UTF-8 valid characters from clients.

The problem is some clients (mainly hackers) are sending all the wrong kind of

Answer 1

Just in case of someone has the same problem. I'am using vim with YouCompleteMe, failed to start ycmd with this error message, what I did is: export LC_CTYPE="en_US.UTF-8", the problem is gone.