解决方法：
修改devenv.exe.config文件，添加 <servicePointManager expect100Continue="false" />
C:Program Files (x86)Microsoft Visual Studio 11.0Common7IDEdevenv.exe.config
<system.net>
<settings>
<ipv6 enabled="true"/>
<servicePointManager expect100Continue="false" />
</settings>
</system.net>