megamenu working on ie but not on chrome and ff

Greeting to everybody on this forum! I would like to inquire about this issue i am having with the megamenu working on internet explorer but not on chrome (half of the time the menu does not open – does nothing but sometimes when i use open on another tab it works- i can see the down arrow button and the menu opens up) and firefox.

Would anybody want to check on this please or if anybody has any suggestions. Thanks a lot.