I'll try to help you as best as I can. This might look like a hack attempt, but trust me, I am doing it purely out of kindness of my heart.
First off, I will put this part in bold and caps, because it's
very important:
FORGET ABOUT GAMECENTER/MY.COM LAUNCHER/WHATEVER THIS MONSTROUS, HIDEOUS THING IS CALLED. IT'S T-R-A-S-H. TRASH.
DELETE IT.
NOW.
When that's out of the way...
Back in the old days, we used to have a functional, small, nice looking and problem-free launcher. That launcher is available for the Russian version even today, but administration of international version thought it will be a good idea to get rid of it.
Note to administration: It was a terrible idea. Allow the old launcher to be downloaded from official site just like the Russian version.
This old launcher still works, only you can't get it anywhere except from old players who still have it or players with a functional installation of the game.
I am sharing it for the english client here:
https://drive.google.com/file/d/0B5gEbhmn3G5Hb1pTNWF5ZjVtUXM
I suggest users of other languages to share theirs.
- Download the above .zip
- Put it wherever you wish the game to be on your disk.
- Go to Allods Online/bin folder and run Launcher.exe (it's the official old launcher)
What I put in there is the bare bones of the client, minimum files required to start up the launcher.
Obviously it will detect a lot of files missing and start a repair. You will get error messages. Run it a few times until it starts downloading the missing files.
It should be enough to get your game up and running. If it doesn't - post here why.