On Component Begin Overlap (Box Collision) ?

Again thank you for your reply. I removed NewVar_0, but I had no success. I rebuild the Blueprint from scratch based on your Event Graph (as close as possible) and Rebuild the level, just to in case. At the moment I walk out of the Box Collision I get the same looking error:

LogScript: Warning: Accessed None trying to read property Cube_Ref
    10_Trigger_Box_C /Game/FirstPersonBP/Maps/UEDPIE_0_FirstPersonExampleMap.FirstPersonExampleMap:PersistentLevel.10_Trigger_Box_C_1
    Function /Game/Cookbook/10_Trigger_Box.10_Trigger_Box_C:ExecuteUbergraph_10_Trigger_Box:0015
PIE: Error: Blueprint Runtime Error: "Accessed None trying to read property Cube_Ref". Blueprint:  10_Trigger_Box Function:  Execute Ubergraph 10 Trigger Box Graph:  EventGraph Node:  DestroyActor
LogScript: Warning: Accessed None trying to read property Cube_Ref
    10_Trigger_Box_C /Game/FirstPersonBP/Maps/UEDPIE_0_FirstPersonExampleMap.FirstPersonExampleMap:PersistentLevel.10_Trigger_Box_C_1
    Function /Game/Cookbook/10_Trigger_Box.10_Trigger_Box_C:ExecuteUbergraph_10_Trigger_Box:0015
PIE: Error: Blueprint Runtime Error: "Accessed None trying to read property Cube_Ref". Blueprint:  10_Trigger_Box Function:  Execute Ubergraph 10 Trigger Box Graph:  EventGraph Node:  DestroyActor
LogScript: Warning: Accessed None trying to read property Cube_Ref
    10_Trigger_Box_C /Game/FirstPersonBP/Maps/UEDPIE_0_FirstPersonExampleMap.FirstPersonExampleMap:PersistentLevel.10_Trigger_Box_C_1
    Function /Game/Cookbook/10_Trigger_Box.10_Trigger_Box_C:ExecuteUbergraph_10_Trigger_Box:0015
PIE: Error: Blueprint Runtime Error: "Accessed None trying to read property Cube_Ref". Blueprint:  10_Trigger_Box Function:  Execute Ubergraph 10 Trigger Box Graph:  EventGraph Node:  DestroyActor