(./foo.bbl
./foo.bbl:12: Undefined control sequence.\Hy@pstringURI
l.12 ...refix\url{\url{http://tsunanet.net}}
./foo.bbl:12: Undefined control sequence.
\hyper@linkurl ...Action/S/URI/URI(\Hy@pstringURI
)>>}\relax \Hy@colorlink \...
l.12 ...refix\url{\url{http://tsunanet.net}}
./foo.bbl:12: Undefined control sequence.
\Url Error ->\url used in a moving argument.
l.12 ...refix\url{\url{http://tsunanet.net}}
and, just like me, you go like "WTF, I did
\usepackage{url}
?!". The answer is to NOT use \url
in the URL field... The link will be created automatically anyway.