I had this issue too, but I applied five years before I should have done! (I thought I could use the PMI online to log hours as I earned them).
I received an e-mail from PMI to ask if I was going to complete my application and they just closed the application, when I said not for some time. It means that the website keeps all the information that you have input and when you go back in you just need to reinstate your application, update and submit it.