Auto layout unable to satisfy constraints when activating a segue - ios

Question

I have a custom table view cell with constraints suggested by Auto Layout. In the storyboard all the constraints are marked with blue lines indicating that they have no errors. The tableview launches fine and the layout works but as soon as I hit the cell to activate a segue I get this:
Unable to simultaneously satisfy constraints.
Probably at least one of the constraints in the following list is one you don't want.
Try this (1) look at each constraint and try to figure out which you don't expect;(2)
find the code that added the unwanted constraint or constraints and fix it.
I have not added any code that adds or removes constraints to my layout. All the constraints were auto-added by Auto layout.
The error only shows up when I hit the cell which activates a segue to take the user to the next view. When I hit the back button, the tableview returns but without any constraints.
The segue is set as Show(e.g. Push) in the Attributes Inspector.
Here's the rest of the message:
(Note: If you're seeing NSAutoresizingMaskLayoutConstraints that you don't understand, refer to the documentation for the UIView property translatesAutoresizingMaskIntoConstraints)
(
"<NSLayoutConstraint:0x7ff1c276fec0 UIImageView:0x7ff1c2496b40.top == UITableViewCellContentView:0x7ff1c2496630.topMargin + 15>",
"<NSLayoutConstraint:0x7ff1c276ff10 UIImageView:0x7ff1c2496b40.centerY == UITableViewCellContentView:0x7ff1c2496630.centerY>",
"<NSLayoutConstraint:0x7ff1c24c9a70 'UIView-Encapsulated-Layout-Height' V:[UITableViewCellContentView:0x7ff1c2496630(43.5)]>"
)
Will attempt to recover by breaking constraint
<NSLayoutConstraint:0x7ff1c276ff10 UIImageView:0x7ff1c2496b40.centerY == UITableViewCellContentView:0x7ff1c2496630.centerY>
Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKit/UIView.h> may also be helpful.
2015-01-06 11:35:58.645 FitLift[4174:130902] Unable to simultaneously satisfy constraints.
Probably at least one of the constraints in the following list is one you don't want. Try this: (1) look at each constraint and try to figure out which you don't expect; (2) find the code that added the unwanted constraint or constraints and fix it. (Note: If you're seeing NSAutoresizingMaskLayoutConstraints that you don't understand, refer to the documentation for the UIView property translatesAutoresizingMaskIntoConstraints)
(
"<NSLayoutConstraint:0x7ff1c2494c00 UIImageView:0x7ff1c277c070.top == UITableViewCellContentView:0x7ff1c277bfa0.topMargin + 15>",
"<NSLayoutConstraint:0x7ff1c24a3360 UIImageView:0x7ff1c277c070.centerY == UITableViewCellContentView:0x7ff1c277bfa0.centerY>",
"<NSLayoutConstraint:0x7ff1c24b7010 'UIView-Encapsulated-Layout-Height' V:[UITableViewCellContentView:0x7ff1c277bfa0(43.5)]>"
)
Will attempt to recover by breaking constraint
<NSLayoutConstraint:0x7ff1c24a3360 UIImageView:0x7ff1c277c070.centerY == UITableViewCellContentView:0x7ff1c277bfa0.centerY>
Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKit/UIView.h> may also be helpful.
2015-01-06 11:35:58.646 FitLift[4174:130902] Unable to simultaneously satisfy constraints.
Probably at least one of the constraints in the following list is one you don't want. Try this: (1) look at each constraint and try to figure out which you don't expect; (2) find the code that added the unwanted constraint or constraints and fix it. (Note: If you're seeing NSAutoresizingMaskLayoutConstraints that you don't understand, refer to the documentation for the UIView property translatesAutoresizingMaskIntoConstraints)
(
"<NSLayoutConstraint:0x7ff1c24c4390 UIImageView:0x7ff1c24bc880.top == UITableViewCellContentView:0x7ff1c24bc3d0.topMargin + 15>",
"<NSLayoutConstraint:0x7ff1c24c43e0 UIImageView:0x7ff1c24bc880.centerY == UITableViewCellContentView:0x7ff1c24bc3d0.centerY>",
"<NSLayoutConstraint:0x7ff1c24c7880 'UIView-Encapsulated-Layout-Height' V:[UITableViewCellContentView:0x7ff1c24bc3d0(43.5)]>"
)
Will attempt to recover by breaking constraint
<NSLayoutConstraint:0x7ff1c24c43e0 UIImageView:0x7ff1c24bc880.centerY == UITableViewCellContentView:0x7ff1c24bc3d0.centerY>
Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKit/UIView.h> may also be helpful.

Answer 1

From the error log, it seems the two conflicting constraints are the image view's top constraint and centerY constraint. Choose only one--iOS is confused what value to assign to the image view's y-coordinate. Do you want the image view to be a certain distance from the top, or to be a certain distance from the superview's vertical center?
As a general rule, if you want your UI to look the way you want to, DO NOT let Xcode auto-add the constraints for you. Define it yourself. We can't really help you here because we don't know the other constraints that Xcode added but don't conflict.

Answer 2

Try lowering one of your vertical constraint priorities to 999 or less.
"<NSLayoutConstraint:0x174091d00 V:|-(10)-[UILabel:0x14562e580'This'] (Names: '|':UITableViewCellContentView:0x17418d5b0 )>",
"<NSLayoutConstraint:0x174091e40 UITableViewCellContentView:0x17418d5b0.bottomMargin >= UILabel:0x14562e580'This'.bottom + 200>",
"<NSLayoutConstraint:0x17408c940 'UIView-Encapsulated-Layout-Height' V:[UITableViewCellContentView:0x17418d5b0(43.5)]>"
I was getting this, notice the last one, encapsulated height 43.5, I'm guessing its a default height, and if your vertical constraints don't fit within that 43.5, the error is thrown. I'm still uncertain how the self sizing cells work, but lowering priorities silenced the warning. I tested a cell shorter than the 43.5 and it also silenced it.

Answer 3

I had a similar problem and it was fixed by setting the tableview's estimatedRowHeight. The default 43.5 wasn't enough to even cover the fixed number of points I set (e.g., my top label in the cell was 10 points from the top of the cell, the bottom label was 10 points from the bottom, and space between rows of labels, etc.)