We’ve found an issue where if you have unicode characters in Android certificate key passphrase or keystore passphrase then the build is failing. The issue is being fixed, but meanwhile we ask that you do not use non ASCII characters in key passphrase or keystore passphrase when you create a new certificate. If you have already created a new certificate we ask that you delete that and create a new one with only ASCII characters in alias, and pass phrasses.
If you had converted a legacy certificate with unicode in alias, key passphrase or keystore passphrase, you have couple of options.
1) Reconvert the legacy certificate: (If you have used the legacy certificate earlier to publish an app and you need the certificate to make updates then use this option)
2) Create a new certificate (If you do not have apps in store that use the legacy certificate then use this option)