Share 'Can chocolate go rancid/ taste off once opened- Please help !'

Hi I am trying to work with chocolate in a high humidity country. ( between 60 and 80 %) I was wondering what is the normal shelf life of chocolate once you open it from the manufacturers packet. I normally keep it well sealed in an air tight container and the room temp. is normally between 20-27 maximum. I know I may need to invest in cold storage for the chocolate. But, it has really been bothe…