Copy Paste Advance Editor Wouldn't Work / Custom Calculation Table Return Error

Does anyone has the same issue to replicate conditioning table on several Power BI files ?

I can replicate renamed collumn, rounded, changed type, but not conditional collumn or additonal collumn.

Below is my partial advance editior text : Any errors ?

#"Added Custom3" = Table.AddColumn(#"Rounded Off2", "Rev Volume US$", each [#"Volume US$"]*0.9),
#"Changed Type3" = Table.TransformColumnTypes(#"Added Custom3",{{"Rev Volume US$", Currency.Type}}),
#"Added Conditional Column" = Table.AddColumn(#"Changed Type3", "Customer", each if [#"Channel / End User"] = "End User" then [#"Channel / End User"] else [End User]),
#"Added Custom4" = Table.AddColumn(#"Added Conditional Column", "Delivery-Close Date", each [Delivery Date]-[Expected Close Date]),
#"Added Conditional Column1" = Table.AddColumn(#"Added Custom4", "B&S", each if [#"Delivery-Close Date"] < #duration(90, 0, 0, 0) then "Yes" else if [#"Delivery-Close Date"] <= #duration(0, 0, 0, 0) then "Date Error" else if [#"Delivery-Close Date"] = null then "Date Error" else "No"),
#"Added Conditional Column2" = Table.AddColumn(#"Added Conditional Column1", "Op1", each if [#"FC%"] = "100%" then 1 else if [#"FC%"] = "80%" then 1 else if [#"FC%"] = "60%" then 1 else if [#"FC%"] = "40%" then 2 else 0),
#"Added Conditional Column3" = Table.AddColumn(#"Added Conditional Column2", "Op2", each if [#"DP%"] = "100%" then 1 else if [#"DP%"] = "80%" then 1 else if [#"DP%"] = "60%" then 1 else 0),
#"Added Conditional Column4" = Table.AddColumn(#"Added Conditional Column3", "Custom", each if [Op1] = [Op2] then "Commited" else if [Op2] = 0 then "Non Commited" else "Upside")
in
#"Added Conditional Column4"

Besides, I am trying to calculate number of days from : Delivery Date - Expected Date, because some of my date filed is not filled, hence some result returned null. Then when I performed IF Function with the conditional collumn: If Delivery Date - Expected Date = null, Power BI will return Error, that is when my Power BI will have refresh error. Shown in the print screen on left.