Sorry about the confusion. You need to click on your name in the upper right corner of your account and go to your Settings, on the Contact Info page, click Edit next to Location and complete the form with your information. Once you update it, you shouldn't receive the warning message anymore.
Hello Valeria, I'm having the same problem! Im not able to send any proposal because of that but once I try to fill in my adress in the settings the button UPDATE dont work. I have not been able to sendo any proposal since the first day I've registered, 4 days ago. Thank you! Larissa