I'm having trouble with BattlEye in Fortnite.

BattlEye is an anti-cheat service Fortnite uses to detect players who use external cheats to gain an advantage in Fortnite.

If you can't start or install BattlEye, or if you're having other issues with BattlEye, check the BattlEye FAQ here which answers most questions. If the FAQ doesn't answer your question, you can email them from their support site here.