This Class Is Not Key Value Coding-Compliant with @Ibinspectable

this class is not key value coding-compliant when using SideMenu pod in interface builder

The “this class is not key value coding-compliant” error almost always means that you are trying to set a property of a custom subclass in your storyboard or XIB file in Interface builder, but forgot to change the class of your object to the custom class. It's easy to get this error if you use "user defined runtime attributes" to set properties on your objects, but don't set the class of the object correctly.

I'd have to look at the project - and specifically it's Storyboards/XIB files, to find the problem, but that's very likely what's going on.

this class is not key value coding-compliant for the key name.'

Key-value coding depends on Objective-C, and under Swift 4 and the new Objective-C inference rules, your name and email properties will not be available.

You can mark individual properties as @objc:

@objc var name: String?

or you can say that everything in the class is available:

@objcMembers
public class Users: NSObject {

Xcode - How to fix 'NSUnknownKeyException', reason: … this class is not key value coding-compliant for the key X error?

Your view controller may have the wrong class in your xib.

I downloaded your project.

The error you are getting is

'NSUnknownKeyException', reason: '[<UIViewController 0x3927310> setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key string.'

It is caused by the Second view controller in MainWindow.xib having a class of UIViewController instead of SecondView. Changing to the correct class resolves the problem.

By the way, it is bad practice to have names like "string" in Objective-C. It invites a runtime naming collision. Avoid them even in once off practice apps. Naming collisions can be very hard to track down and you don't want to waste the time.

Another possible reason for this error: when copying & pasting elements from one controller into another, Xcode somehow keeps that link to the original controller, even after editing & relinking this element into the new controller.

Another possible reason for this error:

Bad Outlet.

You have either removed or renamed an outlet name in your .h file.

Remove it in .xib or .storyboard file's Connection Inspector.

One more possible reason

(In my case) Extension of UIView with bindable properties and setting values for those bindable properties (i.e. shadow, corner radius etc.) then remove those properties from UIView extension (for some reason) but the following <userDefinedRuntimeAttributes> remained in xml (of foo.storyboard):

<userDefinedRuntimeAttributes>
  <userDefinedRuntimeAttribute type="color" keyPath="shadowColor">
      <color key="value" white="0.0" alpha="1" colorSpace="custom" customColorSpace="genericGamma22GrayColorSpace"/>
  </userDefinedRuntimeAttribute>
  <userDefinedRuntimeAttribute type="number" keyPath="shadowOpacity">
      <real key="value" value="50"/>
  </userDefinedRuntimeAttribute>
  <userDefinedRuntimeAttribute type="point" keyPath="shadowOffset">
      <point key="value" x="5" y="5"/>
  </userDefinedRuntimeAttribute>
  <userDefinedRuntimeAttribute type="number" keyPath="shadowRadius">
      <real key="value" value="16"/>
  </userDefinedRuntimeAttribute>
  <userDefinedRuntimeAttribute type="number" keyPath="borderWidthValue">
      <real key="value" value="0.0"/>
  </userDefinedRuntimeAttribute>
</userDefinedRuntimeAttributes>

Solution: Right click on foo.storyboard > Open as Source Code > search by keyPath (i.e. shadowRadius) > Delete the </userDefinedRuntimeAttributes> that causing the problem

How can I fix this warning msg. Warning: Ignoring user defined runtime attribute for key path radius on instance of UIButton

It's working for me:

import UIKit

@IBDesignable
class DesignableView: UIView {
}

@IBDesignable
class DesignableButton: UIButton {
}

@IBDesignable
class DesignableLabel: UILabel {
}

extension UIView {

@IBInspectable
var cornerRadius: CGFloat {
    get {
        return layer.cornerRadius
    }
    set {
        layer.cornerRadius = newValue
    }
}

@IBInspectable
var borderWidth: CGFloat {
    get {
        return layer.borderWidth
    }
    set {
        layer.borderWidth = newValue
    }
}

@IBInspectable
var borderColor: UIColor? {
    get {
        if let color = layer.borderColor {
            return UIColor(cgColor: color)
        }
        return nil
    }
    set {
        if let color = newValue {
            layer.borderColor = color.cgColor
        } else {
            layer.borderColor = nil
        }
    }
}

@IBInspectable
var shadowRadius: CGFloat {
    get {
        return layer.shadowRadius
    }
    set {
        layer.shadowRadius = newValue
    }
}

@IBInspectable
var shadowOpacity: Float {
    get {
        return layer.shadowOpacity
    }
    set {
        layer.shadowOpacity = newValue
    }
}

@IBInspectable
var shadowOffset: CGSize {
    get {
        return layer.shadowOffset
    }
    set {
        layer.shadowOffset = newValue
    }
}

@IBInspectable
var shadowColor: UIColor? {
    get {
        if let color = layer.shadowColor {
            return UIColor(cgColor: color)
        }
        return nil
    }
    set {
        if let color = newValue {
            layer.shadowColor = color.cgColor
        } else {
            layer.shadowColor = nil
        }
     }
   }
}