I'm trying to make it so every time a player places a gray glazed terracotta (money generator), it gives them $1 every 5 seconds, I want that very specific placed block to be bound to the player, so when builders destroy gray glazed terracotta it doesn't send them a message, and also, for the $1 to be added only when the player is online.

This code I got seems to just crash the server when the player who placed the block goes offline.

Code (Text):

1. on place:
2.     set {_location} to event-location
3.     if type of event-block is gray glazed terracotta:
4.         set {generators::%{_location}%} to {_location} #save location
5.         send "&6&l(!) &eTier I Generator has been placed!" to player
6.         while player is online:
7.             while block at {_location} is a gray glazed terracotta:
8.                 wait 5 seconds
9.                 add 1 to player's balance
10.     else if type of event-block is air:
11.         delete {generators::%{_location}%}
12.         send "&6&l(!) &eTier I Generator has been removed" to event player