How do I enable index downloads in Eclipse for Maven dependency search?

I am using Eclipse Oxygen

When I search for dependencies, I get the following warning (also see the screenshot after):

Index downloads are disabled, search result may be incomplete.

 Solution

1. In Eclipse, click on Preferences, and then choose Maven in the left side.
2. Check the box "Download repository index updates on startup".
   • Optionally, check the boxes Download Artifact Sources and Download Artifact JavaDoc.
3. Click OK. The warning won't appear anymore.
4. Restart Eclipse.
5. If not work, Rebuild the index.