Warning : When checking operator: When binding input interface field ... to field ...: Implicit conversion from source type "int64" to result type "decimal[18,0]": Possible range limitation.

Warning : When checking operator: When binding input interface field "field_name" to field "field_name": Implicit conversion from source type "int64" to result type "decimal[18,0]": Possible range limitation.

It means you are trying to convert a bigint to decimal which requires a explicit treatment. Use the AsInteger() function, or assign the column to a stage variable and then use the stage variable to populate the column in the target.