How to fix this error?

[standoff2Developer (model3)]

local Spawner = game.Workspace:FindFirstChild("DealershipPart")
Spawner.ProximityPrompt.TriggerEnded:Connect(function()
    script.Parent.Enabled = true
end)```

[Dlbsp1983 (DLB)]

Has it loaded yet? Might be a timing thing.

[Haydz6 (Cookie)]

This is because you have StreamingEnabled turned on.
Either disable it (property under workspace) or you can read about how to work with it here: Instance Streaming | Documentation - Roblox Creator Hub

[Erex_147 (Erex)]

try manually giving the player network ownership

[standoff2Developer (model3)]

Thank you so much!!!

[Iemny]

As @Haydz6 mentioned, it could be your StreamingEnabled option.

If that does not fix the issue, try changing your first line of code like so, changing the FindFIrstChild() to WairForChild() to give it time to load.

local Spawner = game.Workspace:WaitForChild("DealershipPart")