I have a project which I developed under Xcode 6. Since only Xcode 7 lets me install apps on a physcial device without developer programm, I opened the same project that ran without errors in Xcode 6 in Xcode 7 and got 35 issues. I didn't want to resolve them so I closed the Beta version. Even though nothing was changed in the source code, I still got 24 issues when I opened the same project that before ran smoothly in Xcode 6 when reopening in Xcode 6, stuff like "println has been changed to print", even though it's still Xcode 6. Does anybody know how to fix this issue? Even the SplitViewController template produces a whole lot of errors!
The correct answer was posted in the comments to my question by the user Avt:
Press Alt+Shift+Cmd+K to clean build folder. Then recompile. – Avt