This answerhub post both describes the fix and gives one work around:
https://answers.unrealengine.com/questions/170123/second-player-cannot-be-controlled-when-window-is.html
Another work around is something as follows in the playercontroller.
This answerhub post both describes the fix and gives one work around:
https://answers.unrealengine.com/questions/170123/second-player-cannot-be-controlled-when-window-is.html
Another work around is something as follows in the playercontroller.