I think Demise of Nations is a great game. I wanted to mod it to make a map so I tried to buy modding, but it kept giving me "Error during purchase: java.lang.Exception null (null)" so I tried a couple of times. I restarted the game, my computer, and steam a couple of times. After continuing to get the error, I tried to purchase a couple of other purchases. I tried to buy the 15 dollar purchase with all the maps and modding, but that didn't work. So I tried buying coins to buy the feature with. When that didn't work, I gave up. Several minutes later I got emails saying I had bought "modding" two separate times, and got 2000 coins as well. I am kind of upset that this happened, but it wasn't that much money.
I just wanted the developers to know, I am not sure if this was a Steam problem or a game problem, but steam worked fine, I could buy other things. Have any players had similar problems? I still want the other maps, but now I don't have any money in my Steam wallet and only 2101 coins, not the 2499 need to buy all the maps.