on place:
if player's held item is coal block named "&7Coal Gen &8- &7[&a1&7]":
if {GenCount.%player%} < {@DefaultMaxGens}:
add 1 to {GenCount.%player%}
add location of event-block to {Gens::%player%} # Problem
Here is the code, i can't add the event-block to a list variable
Edit: theres no errors