What is this error?? Help me debug!

I am trying to implement a keypad using Tesla Dev’s method The only thing i am doing differently is that i threw out the raytracing and am using a begin overlap+F key combo to kick things off.

It compiles just fine but when i try to use the keypad i get this error, can someone explain what it means?

Error Blueprint Runtime Error: Accessed None trying to read property KeyPad_BP from function: ‘ExecuteUbergraph_BuildingEscape’ from node: Use Keypad in graph: EventGraph in object: BuildingEscape with description: Accessed None trying to read property KeyPad_BP <—Use Keypad BP <—Keypad BP <----Password UI BP <----Door BP

These errors are usually caused by bad/failed casting or improperly set up references . So make sure you’re reference variables are setup properly , are not null and valid.

Also you get these errors if for example you are trying to access a private variable or function from outide it’s derived class or bp class therefore you may have to make the variable or function public

Are you on the unreal course by any chance ? I noticed you’re project name is escape the room :-p

Yes i am going through that course actually lol.
The references would be the things like the variable DoorBP in the keypad blueprint?
Also how to i check if the variable or function is private or public through the blueprints?
Im very new to Unreal Engine so im still learning all this stuff.

I’ve been playing with it and im pretty confident the problem lies here with the Keypad BP and Use Keypad,
but i dont see what is wrong

oh cool i thought so. i am taking the course as well. its quite fun.

if that’s where you think the problem is start trying to do some debugging like shown in the screenshot


also what variable is keypad BP?? is it a reference if so where are you setting this reference?
what you could try instead is from the true branch do a cast to keypad BP and see if the cast succeeds or fails