Error: Effect named is missing or does not exist

Hey all, I require a bit of a assistance and have been a bit stumped by an error which I'm getting on a project that I've been working on. I'm trying to create a MOGRT with selection controls but have been getting an error which states:

"After Effects warning: Expression disabled. Error at line 30 in property 'Opacity' of layer 12. Error: effect named 'Player Selection' is missing or does not exist. It may have been renamed, moved, deleted or the name may have been mistyped."

Here is the code below, which, as far as I can see, is all correct. All the layers are named right and spelt right so i'm not entirely sure as to why I'm still getting this error pop up.  My language knowledge is amateur at best so it might be something really simple. 

thisComp.layer("CONTROL").effect("Player Selection").compositingOption.effectOpacity

player_selection = thisComp.layer("CONTROL").effect("Player Selection")("Menu");
player = Math.floor(effect("Player Selection")("Menu"));
t = 0;
if(player == player_selection){
t = 100
}
else{
t = 0
}

t

Any help would be absolutely appreciated, thank you.