PPA uploading failed

With which key was the changes file signed? Are you sure it's on keyserver.ubuntu.com and linked to your Launchpad account?

The fingerprint of the key is: 450754FB

Available here and linked to my launchpad account (noplay):
http://keyserver.ubuntu.com:11371/pks/lookup?fingerprint=on&op=index&search=0xA474AF21ACE5BE35574C8C6A0898C847450754FB

Thanks for the help

I found something.

The email used in the deb changelog seem to have been linked to a different launchpad account (julien-x). I don't remember to create it and have no email archive about this.

In the settings of my main account I have been asked to merged the two account. I just merged it but for the moment it's change nothing.

What's the full output of dput?

vagrant@vagrant-ubuntu-trusty-64:~$ dput -Pd ppa:gns3/ppa gns3-server_1.4.6~trusty2_source.changes
D: dput 0.9.6
D: Login: vagrant
D: Parsing Configuration File /etc/dput.cf
D: Parsing Configuration File /home/vagrant/.dput.cf
D: Checking if a host was named on the command line.
D: Host ppa found in config
D: File: /usr/share/dput/rsync.py
D: Base: rsync
Imported: /usr/share/dput/rsync.py
D: File: /usr/share/dput/ftp.py
D: Base: ftp
Imported: /usr/share/dput/ftp.py
D: File: /usr/share/dput/sftp.py
D: Base: sftp
Imported: /usr/share/dput/sftp.py
D: File: /usr/share/dput/local.py
D: Base: local
Imported: /usr/share/dput/local.py
D: File: /usr/share/dput/https.py
D: Base: https
Imported: /usr/share/dput/https.py
D: File: /usr/share/dput/scp.py
D: Base: scp
Imported: /usr/share/dput/scp.py
D: File: /usr/share/dput/http.py
D: Base: http
Imported: /usr/share/dput/http.py
D: Validating contents of changes file /home/vagrant/gns3-server_1.4.6~trusty2_source.changes
D: Architecture: source
D: dsc-File: gns3-server_1.4.6~trusty2.dsc
D: .changes-File: /home/vagrant/gns3-server_1.4.6~trusty2_source.changes
D: .dsc-File: /home/vagrant/gns3-server_1.4.6~trusty2.dsc
Checking signature on .changes
gpg: Signature made Mon 02 May 2016 07:17:36 AM UTC using RSA key ID 9E07F5E8
gpg: Good signature from "Julien Duponchelle <email address hidden>"
gpg: aka "Julien Duponchelle <email address hidden>"
gpg: aka "[jpeg image of size 12831]"
gpg: aka "Julien Duponchelle <email address hidden>"
gpg: aka "Julien Duponchelle <email address hidden>"
gpg: aka "Noplay <email address hidden>"
gpg: WARNING: This key is not certified with a trusted signature!
gpg: There is no indication that the signature belongs to the owner.
Primary key fingerprint: A474 AF21 ACE5 BE35 574C 8C6A 0898 C847 4507 54FB
     Subkey fingerprint: C149 ED3D 14BA 7D5D 87DC E792 CE8B 2963 9E07 F5E8
Good signature on /home/vagrant/gns3-server_1.4.6~trusty2_source.changes.
Checking signature on .dsc
gpg: Signature made Mon 02 May 2016 07:17:30 AM UTC using RSA key ID 9E07F5E8
gpg: Good signature from "Julien Duponchelle <email address hidden>"
gpg: aka "Julien Duponchelle <email address hidden>"
gpg: aka "[jpeg image of size 12831]"
gpg: aka "Julien Duponchelle <email address hidden>"
gpg: aka "Julien Duponchelle <email address hidden>"
gpg: aka "Noplay <email address hidden>"
gpg: WARNING: This key is not certified with a trusted signature!
gpg: There is no indication that the signature belongs to the owner.
Primary key fingerprint: A474 AF21 ACE5 BE35 574C 8C6A 0898 C847 4507 54FB
     Subkey fingerprint: C149 ED3D 14BA 7D5D 87DC E792 CE8B 2963 9E07 F5E8
Good signature on /home/vagrant/gns3-server_1.4.6~trusty2.dsc.
D: Package Version: 1.4.6~trusty2
D: File to upload: /home/vagrant/gns3-server_1.4.6~trusty2.dsc
D: Checksum for /home/vagrant/gns3-server_1.4.6~trusty2.dsc is fine
D: File to upload: /home/vagrant/gns3-server_1.4.6~trusty2.tar.gz
D: Checksum for /home/vagrant/gns3-server_1.4.6~trusty2.tar.gz is fine
D: Checking: distribution trusty matches (?!UNRELEASED)
D: File to upload: /home/vagrant/gns3-server_1.4.6~trusty2_source.changes
D: Default Method: ftp
D: Host Method: ftp
D: Login anonymous from section ppa used
Uploading to ppa (via ftp to ppa.launchpad.net):
D: FQDN: ppa.launchpad.net
D: Login: anonymous
D: Incoming: ~gns3/ppa
D: FTP port: 21
D: Using passive ftp
D: FTP-Connection to host: ppa.launchpad.net
D: Directory to upload to: ~gns3/ppa
D: Uploading File: /home/vagrant/gns3-server_1.4.6~trusty2.dsc
  Uploading gns3-server_1.4.6~trusty2.dsc: done.
D: Uploading File: /home/vagrant/gns3-server_1.4.6~trusty2.tar.gz
  Uploading gns3-server_1.4.6~trusty2.tar.gz: done.
D: Uploading File: /home/vagrant/gns3-server_1.4.6~trusty2_source.changes
  Uploading gns3-server_1.4.6~trusty2_source.changes: done.
D: Writing logfile: /home/vagrant/gns3-server_1.4.6~trusty2_source.ppa.upload
Successfully uploaded packages.
D: dinstall: 0
D: Host Config: False
vagrant@vagrant-ubuntu-trusty-64:~$

Correct by resending the key to the ubuntu server it's work