It would help if you showed us the program, especially around line 163. An error message without knowing what it refers to isn't very useful.
As a guess, 'unprintable' suggests you are trying to print something and the print routine doesn't like the character 0xA0. Perhaps it only accepts ascii characters in the range 0x00 to 0x7F.
In your headline you tak about "0x0A" which as ASCII code represents a newline.
But in the error descriptions there you talk about "0xA0" ... which may be an invalid character