Try this:
1: Delete .M2 Content 2: Set the Proxy configuration in settings.xml
<proxies>
<proxy>
<active>true</active>
<protocol>http</protocol>
<host>proxy.com</host>
<port>xxxx</port>
<nonProxyHosts>local.net</nonProxyHosts>
</proxy>
</proxies>
Be careful! don't put any username and passowrd if proxy is without auth
3: Close Eclipse..and reopen
4: clean and update project configuration
5: verify the java buld path used for the project configuration
6: Try use the Maven embedded in eclipse just for a test, to see if the problem is the external Maven installation corrupted