Hey! Hands of War 3 developer here. I tried to recreate the problem you're having, but I've had no luck. There must have been something corrupt with the data that was saved to your account in that save file. I would first make sure that you're using the latest Flash Player - using older versions causes unexpected things to occur.
There are three save slots for both online and local saving. Can you just use one of the other save slots to restart your game?
