对于那些仍然在Xcode8中与这个问题作斗争的人。对于我来说，这是一个重复的证书问题，这是我解决它的方法:

我读了尼克的回答，然后开始了我的调查。我检查了我的特定案例中的所有密钥和证书(在~/Library/Keychains/System.keychain中)。

When I opened the file, I found that I had two iPhone Distribution Certificates (that was the certificate that Xcode was requesting me), one with the iOS Distribution private key that I have been using since the beginning, and another iPhone Distribution Certificate which its private Key had a name (iOS Distribution:NAME) that wasn´t familiar for me. I deleted this last certificate, started Xcode again and the problem was gone. xCode wasn´t able to resolve that conflict and that´s why it was giving signing certificate error all the time.

检查你的钥匙链，也许你有一个重复的证书。

我也有同样的问题，原因是佩妮。在生成设置中选择了错误的配置文件和证书。我几天前才这么做过。所以，你不需要在xcode中启用“automatic”。在执行此操作之前，请检查构建设置中的配置文件。

我有我撤销的证书的剩余私钥，证书没有了，但私钥没有。删除它们就解决了问题。

要找到他们:

打开钥匙串访问 点击左侧菜单类别下的“键” 寻找未绑定证书的iOS Developer:…"密钥 我删除了它们，问题就解决了

图中高亮显示的密钥是一个没有证书的样例私钥。

Delete the developer certificate that does not have a private key. Delete the provisioning profile from your machine using go to folder (~/Library/MobileDevice/Provisioning Profiles) Then first check then uncheck the Automatically manage signing option in the project settings with selecting team. Sing in Apple developer account and edit the provisioning profile selecting all available developer certificates then download and add to XCODE. Select the provisioning profile and code signing identity in project build settings

我取消勾选，然后勾选“自动管理签名”选项。这为我解决了问题。

如果您尝试将应用程序上传到iTunes Connect(您的供应配置文件设置为分发)，请转到项目设置->构建设置->代码签名。请确保将所有调试和发布选项设置为您的分发配置文件。