ssc install synth, replace
unexpected end of file
http://fmwww.bc.edu/repec/bocode/s/ either
  1)  is not a valid URL, or
  2)  could not be contacted, or
  3)  is not a Stata download site (has no stata.toc file).
r(612);
作为小白想请问一下这样应该如何处理呢？