From looking at what you’ve provided, the only thing that seems like it could possibly cause this would be the “Object” result of “Object in Front of Camera”. It seems that even if the linetrace fails to touch anything, it’ll still try to move forward with the rest of the function and make use of that output, although it is likely null in that scenario. When you try to reference a null pointer, it’ll always cause an access violation.
I would suggest setting up a boolean to store the Return Value of the LineTraceForObjects node and then check that before the Branch you currently have directly after it, only executing the rest of the function if it’s True. Could go a bit further debugging purposes and add a Print String onto the False end of the branch to let you know it failed.
Edit: Or if you would rather avoid creating another variable, have the function also return a boolean and use that.