STOPOVERS 2 FREE STOPOVERS PERMITTED ON THE PRICING UNIT - 1 IN EACH DIRECTION IN FRA/MUC/GVA/VIE/ZRH/BRU/BER/DUS/LIS/OPO/ REK/PDL.
It errors out when I hit purchase on UA.com, tried a lot of different combos and dates...
EDIT: It actually worked, but not on my ideal dates....