the project icon which we see i.e projectname.xcodeproj, is actually a
directory, you do this
1. in terminal do cd yourproject.xcodeproj
2.ls
3.vi
project.pbxproj
4. scroll down till /* Begin PBXContainerItemProxy section
*/
5.there you will see all sections check for the section which is missing a
portal key edit it and save it :wq it will work
in image if you see the first section is missing container portal key.just pic
it from other section and replace it.. it will work