Swati Sharma Thank you for the link Swati! It looks like there is missing content on some of these pages which is why they cannot be completed. Please try talking to your course administrator and let them know which pages you are having trouble with. Here is a link to their profile page: https://www.openlearning.com/u/nuraizaismail
You can leave a comment there or send them a private message. If they do not answer you, please let me know and I will do my best to help you out further.