Zwiebel had a couple of code wipes, where you have to play a specific version of the map with both save systems to convert the save from the old system to a new one, so depending on how many versions ago you played you may have to basicly convert your code 3-4 times from one version to another. The codes are also bound to your username so make sure it's the same as the one you had on the older wc3 with friends.