[UILabel copyWithZone:]: unrecognized selector sent to instance

错误提示如下：

2014-05-23 00:39:09.083 Attributor[1266:70b] -[UILabel copyWithZone:]: unrecognized selector sent to instance 0x8c19bf0

2014-05-23 00:39:09.087 Attributor[1266:70b] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[UILabel copyWithZone:]: unrecognized selector sent to instance 0x8c19bf0'

问题出在我一开始命名了一个

@property (weak, nonatomic) IBOutlet UILabel *title;

后来直接自己把title改成其他名字，所以一直找不到答案。。

解决方法，通过refactor 修改title 名字，或者referencing Outlets 中删除title这个outlet，重新建立，改名字...