i have a v4 and v4.5. the same thing happened to my v4.5. you can still play with your v4.5, just press the button thing in the back and press download. you can still play with the last bit of your battery. look at your instructions and buy the battery. then unscrew the back, and you have 30 seconds to change the battery, otherwise you will lose everything. then, press download after everything is fixed, and you should have your tamagotchi still. hope i could help! ^_^