"Code sign failed" when trying to download Zoho Creator application as Android Mobile App

"Code sign failed" when trying to download Zoho Creator application as Android Mobile App

Hi All,
I'm trying to download my Zoho Creator 5 Application as an Android Mobile App. I fill the form with keystore credentials, package name, Firebase config, FCM server key. After clicking "Code Sign" button the process of generating the mobile app seems to be started. After some time when I refresh the page I get an error "Code Sign Failed", "Error occured while connecting to the server. Please try again after some time." I have already tried couple times with same result.
What could be the reason? What server connection does the error mention?

Regards,
Pawel