Connecting Macbook Pro to Smartboard with HDMI to VGA doesn't work

Hello!

So I recently brought a hdmi to vga cable, so I could connect my Macbook Pro Retina to the Smartboard in my school. Little did i know that the Macbook didn't recognize/find any monitors. Everyone else's non-Apple laptop can easily connect their laptop to it without any problems. Also, I do have a extra monitor at home, however it uses hdmi to hdmi cable which works perfectly.

I tried looking for alternatives, like cables that goes from vga to thunderbolt, or something similar (I've no experience or what so ever), but i couldn't find anything. :(

Can you guys help me?

Thank you.