errors：The operation couldn't be completed.Unable to log in with account '***'

errors：The operation couldn’t be completed. Unable to log in with account '***'. 
An unexpected failure occurred while logging in (Underlying error code 1100).

这个问题的原因是账户过期了，需要在xcode上再重新登录一下。

点击Mac左上角的xcode标识，选择preferences，弹出如下对话框，重新登录即可。