invalid context 0x0. This is a serious error.

在Tab中的第一个Controller中pop 到root 再 跳转到 其他的(第三个)controller,再点击tab上第一个controller会报错误!

 [self.navigationControllerpopToRootViewControllerAnimated:YES];

AppDelegate*appDelegate =(AppDelegate*)[UIApplicationsharedApplication].delegate;

//[appDelegate setMainUserModel:nil atIndex:3];

[appDelegate.tabbarControllersetSelectedIndex:3];

报如下错误:(还有很多)

: CGContextTranslateCTM: invalid context 0x0. This is a serious error. This application, or a library it uses, is using an invalid contextand is thereby contributing to an overall degradation of system stability and reliability. This notice is a courtesy: please fix this problem. It will become a fatal error in an upcoming update.

Jun 10 10:38:19 51jhome.local JieLin6[864] : CGContextSaveGState: invalid context 0x0. This is a serious error. This application, or a library it uses, is using an invalid contextand is thereby contributing to an overall degradation of system stability and reliability. This notice is a courtesy: please fix this problem. It will become a fatal error in an upcoming update.

Jun 10 10:38:19 51jhome.local JieLin6[864] : CGContextSaveGState: invalid context 0x0. This is a serious error. This application, or a library it uses, is using an invalid contextand is thereby contributing to an overall degradation of system stability and reliability. This notice is a courtesy: please fix this problem. It will become a fatal error in an upcoming update.