A quick hack to accept https connections:

    private static void initSSL( HttpURLConnection httpCon ) throws IOException {
        if( httpCon instanceof HttpsURLConnection ) {
            HttpsURLConnection https = ( HttpsURLConnection ) httpCon;

            try {
                TrustManager[] trustAllCerts = new TrustManager[]{
                    new X509TrustManager() {
                        @Override
                        public X509Certificate[] getAcceptedIssuers() {
                            return new X509Certificate[0];
                        }

                        @Override
                        public void checkClientTrusted( X509Certificate[] certs, String authType ) {
                        }

                        @Override
                        public void checkServerTrusted( X509Certificate[] certs, String authType ) {
                        }
                    } };
                SSLContext sslContext = SSLContext.getInstance( "SSL" ); //NOI18N
                sslContext.init( null, trustAllCerts, new SecureRandom() );
                https.setHostnameVerifier( new HostnameVerifier() {
                    @Override
                    public boolean verify( String hostname, SSLSession session ) {
                        return true;
                    }
                } );
                https.setSSLSocketFactory( sslContext.getSocketFactory() );
            } catch( Exception ex ) {
                throw new IOException( ex );
            }
        }
    }

core-main a1e29ab0536a

and a fix for the demo image: core-main 68e5fe0fdc6c

keeping track of "73patch2-candidate" in case it needs to be backported to 7.3.1

Any progress on serverside revert to http?

Fix itself seems to work fine anyway in NetBeans IDE Dev (Build 201304292301)

The server side should change soon to fix this problem for all previous versions.

However, let's backport these changesets to release73 to make sure that 7.3.1 is OK regardless of any future server changes.

backported to release73 branch as 793c644a4e9d

Integrated into 'releases', will be available in build *201305062200* or newer. Wait for official and publicly available build.
Changeset: http://hg.netbeans.org/releases/rev/793c644a4e9d
User: S. Aubrecht <saubrecht@netbeans.org>
Log: #228202 - backport of a1e29ab0536a and 68e5fe0fdc6c

Verified in 7.3.1 build.

*** Bug 230232 has been marked as a duplicate of this bug. ***