我不确定为什么用这种方法修复了它. 我所做的是我在终端$ xcrun simctl erase all中运行了此命令. 之后，我什至从xcode再次运行我的项目，甚至没有下载任何东西，它就起作用了.

I'm not sure why it's fixed this way. What I did is I ran this command in terminal $ xcrun simctl erase all. After this I run my project again from xcode without even downloading anything and it worked.