For those who use Planning Portal on a regular basis, for planning applications and building regulations information - the Planning Portal website has changed this weekend from planningportal.gov.uk to planningportal.co.uk. What this means is that if you try to search it on Google you may not be able to find it!
Just type https://www.planningportal.co.uk/ into the search bar and you should be redirected to the new site. When you log in you will be asked to change your password, check your junk mail for the temporary password, and eventually you will be able to log in to the new site and see your existing saved planning applications.
Hope that helps for anyone who was having the same problems I was!