Replicated variable not changing issue

Hi, i am new in the forum. I’m working “Tris” type game, player on his turn can preview his symbol (X or O) of an unused space of grid. The problem is, when i click with the mouse on the blank space, the boolean (that prevent player to not set another symbol on the blank space) doesn’t set to true. I used “Run on server” event for that and “Multicast”, but none of them works. Please help! (Blank space is an actor with plane having the X or O texture. Placed in the map).photo_1

You must be the owner of that actor if you want to send server events (RunOnServer), are you sure that’s the case ?