下载xsmle命令时显示
package installation
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package name:  st0470.pkg
         from:  http://www.stata-journal.com/software/sj17-1/

checking st0470 consistency and verifying not already installed...
I/O error
could not copy http://www.stata-journal.com/software/sj17-1/st0470/xsmle.ado
(no action taken)

r(691);

请教一下这是为什么啊，以前没遇到过这种问题。