Without seeing the script that caused this to happen ( if it was even a script ), we will be unable to help you. All I can say from that alone is, you may have a script that runs as soon as a player logs in that attempts to delete a timer that isn't there. But I doubt this is the case since we'd see a debug from the script command.
Another guess is it would be src related since the console is failing to parse the timer at this point. Perhaps someone more knowledge-able can assist with this.