Here in Ether 2:14, the 1837 edition dropped the definite article the before four years. The resulting reading is ambiguous: one can’t be sure whether the text is referring to another four years or the original four years. The earliest text has the definite article the and thus eliminates any possible confusion over the length of time; the total number of years is four.
Summary: Restore the definite article the before four years in Ether 2:14 (“at the end of the four years”).