重新下载代码：（需要梯子）
cap ado uninstall ftools
net install ftools, from("https://raw.githubusercontent.com/sergiocorreia/ftools/master/src/")

* Install reghdfe
cap ado uninstall reghdfe
net install reghdfe, from("https://raw.githubusercontent.com/sergiocorreia/reghdfe/master/src/")

* Install ivreg2, the core package
cap ado uninstall ivreg2
ssc install ivreg2

* Finally, install this package
cap ado uninstall ivreghdfe
net install ivreghdfe, from("https://raw.githubusercontent.com/sergiocorreia/ivreghdfe/master/src/")


无需梯子的下载好的版本见附件（要个币回回血嘿嘿）
具体可参考：https://mp.weixin.qq.com/s/fkrZImzHEu5CSc5LHqTFXw或https://www.zhihu.com/people/zhao-wu-ling-wang-91