Netbeans cannot be activated, may be a network problem, however, can get to the Internet,
Error is as follows:
Network problems in http://plugins.netbeans.org/nbpluginportal/files/nbms/z9817_org-netbeans-modules-nbjavac.nbm

Check the proxy Settings or try again later, the server may be unavailable at present, you may also need to ensure that the firewall does not block network communication, your cache may have expired, please click the "check update" to refresh the content,

Test links, shows the connection fails,

Version is 10.0