XCode 4无法打开旧项目(XCode 4 Unable to Open Old Projects)

我刚刚升级到XCode 4，现在无法查看我以前的XCode 3项目。 当我启动XCode打开的项目时，它看起来像这样：

有什么方法可以告诉出了什么问题？ 我可以看的任何特殊日志？ 我不会收到任何警告或错误！

I just upgraded to XCode 4 and am now unable to view a number of my previous XCode 3 projects. When I launch the projects XCode opens, but it looks like this:

Any way to tell what is going wrong? Any special logs I can look at? I don't get any warnings or errors appearing!