On the non-existence of left-invariant hypercomplex structures on $SU(2)^4$

Using elementary arguments, it is shown that $SU(2)^4:=SU(2)\times SU(2)\times SU(2)\times SU(2)$ admits no left-invariant hypercomplex structures. This result answers (in a very clear way) the question of whether every compact Lie group of dimension $4n$ admits a left-invariant hypercomplex structure. The aforementioned question has apparently been the source of some confusion in the recent literature.