How can I fix that?

I press the “C” (ToggleVisionView) and nothing happened and when I exit the Play I see this notification in Message Log. Where is the problem?

“Blueprint Runtime Error: “Accessed None trying to read property TB2Ref”. Blueprint: TB2_Controller Function: Execute Ubergraph TB2 Controller Graph: GameInput Node: On Toggle Vision View”

Accessed none means you are trying to read TB2REF which has not been set or can’t be read because of error in the code. Would be great if you could make some screenshots and explain the logic (what you want to achieve) behind it.