If your server is experiencing issues with NOT being able to connect to instance server when trying to go through the dark portal..
All you have to do is
1. Get someone from another server to invite you.
2. Let it load you into their server
3. Go through Dark Portal
4. Spread the word.
My server wouldnt let me through the portal on Jubeithos. joined a mate on Dreadmaul and was able to walk through