Sonatype Nexus: Cannot proxy http://milton.io/maven/ -

We are using Nexus for proxy remote magnum repositories. It works well except the Mewen repository of Milton.O.

If I add a repository to my Mayvan settings .xml without using the Nexus, then it works well, the artwork is dragged correctly:

 < Code> & lt; Stores & gt; & Lt; ID & gt; Milton-repo & lt; / Id & gt; & Lt; URL & gt; Http: //milton.io/maven/< / URL & gt; & Lt; / Stores & gt;  

Now if I add the repository to the Nexus as a 'proxy repository' then this does not work. Nexus can not pull essential artifacts:

  Failure to find IO.milton: milton-server-ce: jar: http: // xxx: 8180 / Nexus / content / group / in local store Public cached, until the Nexus updates update has not expired or the update has been compelled, it will not be resolved  

Any ideas why the Nexus this repository Can not Proxy?

Edit: If I look in the Nexus log then this is:

  2015-03-17 11: 05: 05,779 + 0100 info [ar-4-thread -4] Administrator org.sonatype .nexus.proxy.maven.routing.internal.RemoteScrapeStrategy - Not possible the remote scrap of M2Repository (id = melton), no scraper succeeded.  

Note: The proxy repository has been correctly added to the public group.

I'm seeing very poor performance from this server, this process can take about a minute to process Is:

So you're killing the default read timeout of the repository 20 seconds in Nexus

Check out the nexus.log file to see if What are the expiration exceptions. If so, increase the timeout in the "HTTP request settings (optional)" and in the configuration of the repository. It takes 60 seconds with 3 reports as if it could work.