MissingReferenceException: The variable m_AnimatorController of 'AnimatorControllerTool' doesn't exist anymore.

How do I fix this error?

I think I know why it keeps saying that, and it's probably because I deleted all of my animations and animators.

Problem is, I don't know how to fix it. It's not really affecting anything in my game, but everytime I run it, this error just keeps popping up, and it's kind of annoying.

Full error:

 MissingReferenceException: The variable m_AnimatorController of 'AnimatorControllerTool' doesn't exist anymore.
 You probably need to reassign the m_AnimatorController variable of the 'AnimatorControllerTool' script in the inspector.
 UnityEditor.Graphs.AnimationStateMachine.TransitionInspector.OnEnable () (at C:/BuildAgent/work/d3d49558e4d408f4/Editor/Graphs/UnityEditor.Graphs/AnimationStateMachine/TransitionInspector.cs:74)

Thanks :)