Ai is not working when pawn comes into its range! help!!

hi, i was following documentation of making a Ai char where it will move when player comes into its range ref:https://docs.unrealengine.com/latest/INT/Engine/AI/BehaviorTrees/QuickStart/2/index.html … i followed through out the documentation but at the end the character is not moving!

in documentation it says “The AI will just stand around if it hasn’t detected a Pawn that isn’t an AI Character.” i didn’t get what it means but i have tried making my pawn as ai controller in class defaults of my characterBP still it isn’t working can anyone please help…

i attached screenshots of my blackboard and behavior tree… any help will be appreciated ! and sorry for my bad english :frowning:

Is a Navmesh in world?

yes i created nav mesh