Prey won't flee, getting an error message..

Hi I have just started using this A.I. package. I really like the simplicity of it and how well everything is explained through all of the notes but I'm still not getting it to work perfectly. Right now I cant get a prey character to flee. I have a predator that works like its supposed too & it will attack the prey character but the prey character won't flee & I get this error message....

NullReferenceException: GetRef Emerald_Animal_AI.AttackWhileStationary () (at Assets/Emerald AI/Scripts/Emerald AI/Emerald_Animal_AI.cs:2453) Emerald_Animal_AI.MainSystem () (at Assets/Emerald AI/Scripts/Emerald AI/Emerald_Animal_AI.cs:1611) Emerald_Animal_AI.Update () (at Assets/Emerald AI/Scripts/Emerald AI/Emerald_Animal_AI.cs:1758)

It seems the prey character tries to turn & defend itself instead of fleeing just before this error happens.