Why do I get an error when creating a new folder?

When I try to create a new folder, I get the following message: We were not able to add your new folder, please try again later.

I have tried from different browsers and different computers, and also with different internet connections. Right now I'm trying from Chrome, in an incognito tab and my internet speed is 70MB download and 13MB upload.

What could be the problem? Is there a maximum number of folders that can be created?