1.打开idea 打开maven项目报错：Unable to import maven project
2.在idea中Help->Show Log in Explorer->idea.log
Caused by: java.rmi.ConnectException: Connection refused to host: localhost; nested exception is:
3.在windows 的hosts文件输入如下内容：
127.0.0.1 localhost 0.0.0.0 account.jetbrains.com
按照如上步骤在idea中Maven Projects上Reimport即可成功。
intellij idea 2017 Unable to import maven project
原文：http://www.cnblogs.com/fofawubian/p/7928671.html