Error when I install package "pgfplots" with MikTex

I tried to install package "pgfplots" via MikTex, but it was not successful. The error detail is as follows:

Source: LibrariesMiKTeXPackageManagerCurlWebSession.cpp:266

Error: Transferred a partial file

Details: code: 18.
url: https://mirror.yongbok.net/ctan/systems/win32/miktex/tm/packages/pgfplots.tar.lzma

What is the problem? How to solve it? My current MikTex version is 2.9.7200.