I've since my post been able to train at sandcrabs for more than 6hours with the script. Though I still don't know why it kept on banking and logging. I always had a decent stock of combat potions/tuna.. oh well tbh it doesn't matter.
Problem solved. Overall another great script.
and when you said: Open the console to see what went wrong - does it mean the log.. which u can access by simply options>Show Logger? just for future reference, thanks!