Broken campaign - reversal of fortune mission

[Ttandc]

Hi, I am playing through this game for the very first time and on a brand new computer. I have reached a mission called reversal of fortune and have killed the nazgul but the mission says I need to kill 2 enemy captains but no other enemies are on the field, no grunts and no captains. I can't finish the campaign if I can't get past this mission. WB games PLEASE FIX, thanks in advance :)

[Skylance]

try just skipping time at the Towers until the empty spots on the Board are refilled(if you have killed all the captains or branded them.)