Just change code to be like this.
ECSlidingViewController *slidingViewController = self.slidingViewController;
[slidingViewController anchorTopViewOffScreenTo:ECRight animations:nil onComplete:^{
CGRect frame = slidingViewController.topViewController.view.frame;
slidingViewController.topViewController = transferView;
slidingViewController.topViewController.view.frame = frame;
[slidingViewController resetTopView];
}];
this solve problem. I have no idea why... but it's worked.
Thank you :--> Switching views with ECSliding without navigation menu