I've posted this a couple of times. Hopefully it helps.
I had this problem (Was running windows 7 64 bit with 12 gb of ram) and I was able to correct it doing the following.
1) Download and install CFF Explorer.
2) Once installed. Find game.dll (for windows 7 it should be in the following folder. C:\Program Files (x86)\Electronic Arts\Dark Age of Camelot.
3) Right click game.dll and click Open with CFF Explorer.
4) Once that is open, on the top left hand side there will be a thing called File Header. Click it.
5) On the right hand side of that there will be a thing that says click here, click it. A small box will pop up.
6) Down near the middle of the box there is a line that says.. App can handle >2gbaddressest. Make sure that is checked off.
7) Close CFF Explorer.
Save the file game.dll to your desktop.
9) Close windows explorer.
10)Now take the game.dll that is on your desktop and paste it here. C:\Program Files (x86)\Electronic Arts\Dark Age of Camelot.
11) Restart the game and you are golden.
A side note. You might have to do this more than once the firs time as the game might try to undo what you fixed. If this happens just repeat the steps above until it takes. It won't take more than 1-2 times. It's only happened to me once out of more than a dozen times fixing it after DAoC patches.
This has worked for me and several of my friends. Good luck.
Also anytime DAoC has a patch you will have to redo this.
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