I was also experiencing this bank closing issue on only one of my accounts for many days now. Turns out as I'm writing this post to report this issue, I noticed my rune pouch only had 26 dust runes in it, and after filling it, the script is now back up and running with no trouble on this account as well :D. I suggest adding a disclaimer about low rune count in the rune pouch or something ^^.
Thanks alot for this script and your continuous efforts, Chris, the script really is amazing.