invalid character stops the validation

I have an invalid characters on lines x y z and w and this stops the validation with NO indication of what lines x y z and w are.

You do NOT even show me the line of code in reference to the error. This would be so HELPFULL if I could see the actual line that has the error.

I do not know how you interpret what a line constitutes of? Is it from tag to end tag? or does it include all of the blank lines, or spacing,  that I used to make the code
more readable?

Here is your error message:

" Sorry, I am unable to validate this document because on line 18, 193, 196, 199, 202, 206 it contained one or more bytes that I cannot interpret as utf-8 ... "
This is about as informative as error "404 page not found"

THAT'S  all I have to go on. 

Why can't you show the raw line of code with the error? 
I.E:

"Sorry, I am unable to validate this document because on line 18 ....
Display of Line 18 " xxxxx" in it's full context, as you interpreted it

Now I can go right to line 18 in my HTML code and fix it  I know, too simple and too user friendly. 





NOTE: Whenever possible, give the address of the document you were checking.