Every time after start UE deletes all saves in C++. I open classes, use Live Code and they return but after closing i return to classes and no saves. Usually it shows the error: was passed an ObjectPath (/Game/MyFolder/C++_classes_bp/Bp_MyActor.Bp_MyActor) rather than a PackageName or FilePath; it will be converted to the PackageName. Accepting ObjectPaths is deprecated behavior and will be removed in a future release; TryFromMountedName will fail on ObjectPaths.
I believe when you compile with live code and then close the editor you lose your compilation so before you open your project again you need to compile your code and then open the project.