Couldn't load a xcode project because it is already opened from another project or workspace

Question

I have a project that has one target dependency. The target dependency is dependent on a framework called Three20.

The dependency tree looks like this.

Answer 1

Had the same problem in a case where I got a workspace working, closed it, copied the containing folder to a USB drive, then reopened. I got that message for one of the projects in the workspace. Closed, tried again, removed/re-added project - no luck. Closed, tried to open the project alone and got the message about it being open in another workspace - not true. Quit XCode, restarted by double-clicking my workspace in Finder, and all went well after.