I personally haven't had any user report this issue to me but that usually happens when there is a maintenance..
I sugget you do this for now:
1) Use CCleaner [clean and registery scan] If you don't have CCleaner, this is where I got mine.
2) If you don't know how to use CCleaner, let me know I can show you my settings.
3) Once you have cleaned your PC and ran registery scan, restart your computer.
4) If you use Steam, do not use it. Instead got to AeriaGames folder > AVA > NWZLauncher. Start your AVA this way. If you use Ignite, then start your AVA normally.
If these steps still don't help you get on AVA, reply back to this thread.