UE4 - Blueprint Runtime Error. Call_Func_array_Get_Item error.Set simulate physics error

Hello, I’m doing a game, I want a random number of doors (out of 6) in a row to be opened randomly (2 of them) and the others to be closed. In this, I want to disable the physics of my actor and the physics of the randomly selected ones to work. I wrote this to the Levelin blueprint. But I make mistakes === [(Blueprint Runtime Error: “Accessed None trying to read property CallFunc_Array_Get_Item”. Blueprint: DoorGame — Function: Execute Ubergraph Door Game — Graph: Event Graph — Node Set Simulate Physics)] [(Blueprint Runtime Error: “Accessed None”. Blueprint: DoorGame — Function: Execute Ubergraph Door Game — Graph: Event Graph — Node Set Simulate Physics)] Please help. * Note * I’m doing something like Fall Guys Door System …

This is my game view.!
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This is the error list I got when I stopped the game.

https://drive.google.com/file/d/1uferEqK7CJtAcqL_849UAe6SV-p-227Y/view?usp=sharing

This is my door integer.

https://drive.google.com/file/d/1N6ZvNmCvQeUfK6_nlTbedmP26BDKDTnY/view?usp=sharing

In these, my gate row is 6 gates representing a number - a region, and a random gate is chosen from that region. And these are the list that will tell you what I did.

https://drive.google.com/file/d/1pvqHzH2CES6XTdcMRbiPshmRtrUGLzhf/view?usp=sharing

https://drive.google.com/file/d/1KQjA6jcQSe9mpKIFUSnvk6mYh-vOReh6/view?usp=sharing

This Others shows what I did in my level blueprint.

https://drive.google.com/file/d/1CX6o7RyhxslVXM_LD1gQt7tmI_-hy-HW/view?usp=sharing

https://drive.google.com/file/d/1-0eKZ1X73NTJwaZwg-knAQwsVupPeUdR/view?usp=sharing