error : Error: Certification chain Invalid. Trust Chain missing. You should import the intermediate and root certificates.Retry
solution : you have to import certificates from the digital signature supplier like safescrypt or ncode etc and install. then it will work. i had the same issue and got it resolved. for safescrypt the following are to be downloaded and installed
1) https://www.safescrypt.com/drupal/download/SafeScryptRoots.zip
2) https://www.safescrypt.com/drupal/download/SafeScryptCA2014.cer
3) https://www.safescrypt.com/drupal/download/SafeScryptCA2014_subCAs.zip
this solves the issue
regards
ramanathan