There is no such "pdflatex" value for `TeX-engine', did you mean
"default"? If so, it's the default (as the name suggests), so you
don't need to specify it. Which is the first line of the output
buffer (C-c C-l)?
I copy this lines from another project I guess. I don't know why I had pdflatex instead of default. Here is the pastebin of the log : http://pastebin.com/sHNpkRcR