花了一会儿解决这个问题，因为我遇到了同样的问题。

Took me a while to work this one out, as I was having the same issue.

如果你在Xcode中查看它时突出显示你的AppIcon资产组，你可以添加其他字段到它通过打开检查器（右侧窗格）并单击所需的复选框。然后你可以拖动你的图标让它们正常工作。

If you highlight your AppIcon Asset group when looking at it in Xcode, you can add additional fields to it by opening the inspector (right hand pane) and clicking the checkboxes on what you want. Then you can drag in your icons and have them work properly.