Treasure Hunter Step 7: Confusing Bug

So I have made it to Step 7 in the Tresure Hunter game dev project. And up until this step all of the code works exactly like it shows in the hints below each step. But on step 7, creating a for loop:

Create a for loop that defines a variable called x which has a value of 46 . We want our loop to continue if x is less than 437 . Each time we iterate, increase x by 78 . We increase by 78 to ensure our plots fit correctly in the background image and do not touch each other.

Inside of this for loop add this sprite to see what the for loop does.

this.add.sprite(x, 46, 'gold'); 

Once you have finished with this for loop make sure to delete the line that is creating the coin sprites.

This seems to be setting off an unexpected problem. The way I understand is, the for loop I have created

for (x = 46; x < 437; x += 78) {
this.add.sprite(x, 46, 'gold);

}

is supposed to populate fields with coins. But my screen looks as blank as it was previously, the only exception is the score counters have changed to 108 and 22, respectively. I am not sure what I am doing wrong here. Deleting the code fixes the bug so I know it’s an issue with the loop.
Picture showing the error below: