Yay, it worked! I went around in circles for a long time. Then I decided to check one of the boxes in 502A (I chose Retail), next goto "File > Forms" , find 502A, open it, now click on delete at the bottom of the forms page. Then proceed with "Next", "Continue" to the E-Filing and it worked! The important part was I had to first complete 502A by checking a box and then deleting the completed form.
