If hit "Index downloads are disabled, search results may be incomplete." issue.
"Window" --> "Preferences" and choose Maven in the left side.
Now you have to check the box "Download repository index updates on startup"
If no "Search Results"
"Window" ---> "Show View" ---> "Maven Repositories" ---> "Global Repositories"
Index downloads are disabled, search results may be incomplete.
原文：http://www.cnblogs.com/AloneSword/p/4146884.html