Won’t budge when 4×4 engaged

Hey everyone it’s been a while since I posted anything. I have a 03 Foreman 450es with selectable 4×4 was mudding the other weekend and noticed my 4×4 light flashing not realizing it was giving me a code. Kept riding and now when in 4wheel drive it will not go forward or back. But when in 2 wheel drive works fine. Any thoughts?