Thank you Jnm for the response, Indeed, I am on [kf.kobotoolbox.org server. I was afraid of loosing my unsaved work but it appears I have no choice than to log out and login again. The error message changed though to:
Error saving form
Your changes could not be saved, likely because of a lost internet connection. Keep this window open and try saving again while using a better connection.
Sorry to hear that. Did you try logging out and back in again with a different tab in the same browser? If the form still wouldn’t save after doing that, and you had to reload the tab where you were editing the form, then that’s a problem we would like to fix.