libc++abi.dylib: terminating with uncaught exception of type NSException (lldb)

Answer 1

Make sure you are not dynamically applying relative constraints to a view which is not yet there in view hierarchy.

UIView *bottomView = [[UIView alloc] initWithFrame:CGRectZero];
[self.view addSubview:bottomView];

bottomConstraint = [NSLayoutConstraint constraintWithItem:bottomView
                                                attribute:NSLayoutAttributeBottom
                                                relatedBy:NSLayoutRelationEqual
                                                   toItem:self.view
                                                attribute:NSLayoutAttributeBottom
                                               multiplier:1
                                                 constant:0];
bottomConstraint.active = YES;

In above example, bottomView has been made part of view hierarchy before applying relative constraints on it.