Are you from Spain or your Account Location from Spain or any Spanish speaking Country?
Because if it is automatically appending /es-es then it might be Account or Location specific Problem.
Do you have any alternate Account through which you could try?
Since you mentioned that regardless of OS, Browser you are facing same error it might Indicate Location or Account specific Problem which only could be solved by contacting Fab Team through email support.
or maybe you could ask any of your Local Friend who would have Fab Account to see whether or not.
I would recommend sending email for Support to Fab Team.