"out of space" error on a brand new account

I got a marketing email from Adobe to give Express a try and I wanted to try Express and logged in but  whatever I do (add sample images, texts, etc.) I get an error "out of space". I'm on my brand new account, have no data in the cloud and never used Express before. My disk is half empty. Why do I get this error? How do I fix the problem?

I have already tried this thread but it didn't help. Another person there said it was something to do with configuration and Adobe support fixed it. 

https://community.adobe.com/t5/adobe-express-discussions/unable-to-use-adobe-express-because-quot-out-of-space-quot/m-p/14306408#M13631