Adding a new listing to my account.

[Viki1]

 I already have an account with 3 listnings.

I wish to add another listing but when I try this is the message I get! 

Not authorised.

How do I get around this. The place I am told to go does not exist anywhere on the AIrBnB website which is hideously complecated to find your way around at the best of times!

[Marzena4]

Log out, update your browser, clean the cookies and log in again, @Viki1.