connection Macbook pro and led wall on the stage

A week a go I was in a congress before in Russia and then after a couple of day in Azerbaijan and in both cases it wasn't possible to connect my Macbook pro with the led walls (no projector in both cases). The technicians tried to connect my device but it didn't work they changed the resolution and also the MHz but nothing changed. So I transfer my presentation on other computer of my Asian colleagues (Macbook pro) with the same setup and it worked properly. WHY????????? Somebody knows the key to solve this problem? Always when I go in Asia I'm not able to connect my Macbook pro.