I was researching a friend list system, and found this article:
The last line of code at the bottom of the page is as follows:
print("Friends of " .. USERNAME .. ": " table.concat(usernames, ", "))
However, it should instead be:
print("Friends of " .. USERNAME .. ": " .. table.concat(usernames, ", "))
The current code throws an error, because there is not a .. between the ": " and the table.concat