Why does my snow deformation appear delayed and break when the instance goes nil?

I made snow deformation and accomplished it, but I have 2 problems arising from it.

1. When the player jumps or walks too fast, the result turns nil and breaks the whole script. Error Data: Workspace.Player1.Deform:29: attempt to index nil with 'Instance'

2. The deformation appears to be delayed. Error Data: N/A

Heres The Code:

while wait() do
        local R_Result = workspace:Raycast(RFoot.Position, RFoot.CFrame.UpVector * MaxLength, RayParams)
        local L_Result = workspace:Raycast(LFoot.Position, LFoot.CFrame.UpVector * MaxLength, RayParams)

        if R_Result and R_Result ~= nil then
            RAttachment.WorldPosition = R_Result.Position

            if R_Result.Instance then
                if R_Result ~= nil and R_Result.Instance.Parent:IsA("Bone") and L_Result.Instance.Parent.Parent.Name == "Snow" then
                    game.TweenService:Create(R_Result.Instance.Parent, TweenInfo.new(dbTime), {WorldPosition = R_Result.Instance.Parent.WorldPosition - Vector3.new(0,1.5,0)}):Play() -- Error
                end
            end
        else
            RAttachment.WorldPosition = RFoot.Position + (RFoot.CFrame.UpVector * MaxLength)
        end

        if L_Result and L_Result ~= nil then
            LAttachment.WorldPosition = L_Result.Position

            if L_Result.Instance then
                if L_Result ~= nil and L_Result.Instance.Parent:IsA("Bone") and L_Result.Instance.Parent.Parent.Name == "Snow" then
                    game.TweenService:Create(L_Result.Instance.Parent, TweenInfo.new(dbTime), {WorldPosition = L_Result.Instance.Parent.WorldPosition - Vector3.new(0,1.5,0)}):Play() -- Error
                end
            end
        else
            LAttachment.WorldPosition = LFoot.Position + (LFoot.CFrame.UpVector * MaxLength)
        end
    end

All help would be appreciated, I need answers quickly so I can hopefully fix this. Also when the deformation appears delayed should I use a better alternative instead of using the loop

"while wait() do"

Thank you.