修复 Xcode 错误 “The identity used to sign the executable is no longer valid”

如图：

解决方法来自：http://stackoverflow.com/questions/7088441/the-identity-used-to-sign-the-executable-is-no-longer-valid/14275197

Restarting Xcode didn't work for me. What fixed it for me was going to Accounts in Xcode (in preferences), Details for my developer account then clicking the refresh icon at lower left. That loaded a new team provisioning profile, which apparently was needed... yeah. We shouldn't have to deal with this Apple. Microsoft used to do this stuff to developers, don't go there. –  Eskim0 Mar 9 at 3:34

步骤：

1. 打开Xcode配置（Xcode -> Preferences...）
2. 选择Accounts页面，选中你的Apple ID，点右下方的「View Detail...」按钮
3. 点击左下角的刷新按钮，等待刷新完成，点「Done」按钮，关闭Xcode配置窗口
4. 重新编译运行项目，若出现修复窗口，一路点「Fix Issue」按钮

还有其他解决办法，见引用上面的链接。