When I try your file above, there's rather more relevant
stuff in the log file; with the irrelevancy of the particular
path on my computer removed, I see
Package biblatex Info: ... file 'biblatex.cfg' found.
(C:<my irrelevant path>\biblatex\biblatex.cfg
And, in fact, it is in biblatex.cfg that "brazilian" is
"undefined". On my system, biblatex.cfg contains no
definitions; does it on yours? If so (or if it does,
but brazilian and portugues aren't among them), there's
your problem.
Since (obviously) I don't use biblatex, I don't know
what form the definitions should take.
Lee Rudolph