應用軟體更新有問題!!! >

我想更新我應用軟體的版本
從手機上的APP STORE裡的 Updates 去點選更新

但為什麼有的軟體 點下去後會出現
This discounted price is only available to customers who own a previous version of
this item. To purchase this item at full price, click buy

然後點buy以後 又出現以下
This item is currently being modified. Please try again later


每一次點都這樣.....我都隔一段時間在去點 但他還是這樣 = =""

這是哪裡有問題??! ><