This might be caused by bug #918489. Are you able to reproduce the problem with a backup created under 34.2-0ubuntu1.1 or later?
** Changed in: deja-dup (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to deja-dup in Ubuntu. https://bugs.launchpad.net/bugs/1605172 Title: deja-dup ignores passwords repetitively - no backup possible Status in deja-dup package in Ubuntu: Incomplete Bug description: Preset: After a full backup (with passwort protection set), deja-dup cannot create incremental backups. It asks for the password, scans files, then asks for the password again. First described in #1604811 (falsely relating it to duplicity). After the password dialog appeared, deja-dup says: Preparing ... Scanning ... asks for the password again. One can break this loop only by cancelling the backup. No backups possible. ProblemType: Bug DistroRelease: Ubuntu 16.04 Package: deja-dup 34.2-0ubuntu1 ProcVersionSignature: Ubuntu 4.4.0-31.50-generic 4.4.13 Uname: Linux 4.4.0-31-generic x86_64 NonfreeKernelModules: nvidia_uvm nvidia_modeset nvidia wl ApportVersion: 2.20.1-0ubuntu2.1 Architecture: amd64 CurrentDesktop: Unity Date: Thu Jul 21 12:14:58 2016 InstallationDate: Installed on 2013-05-17 (1160 days ago) InstallationMedia: Ubuntu 13.04 "Raring Ringtail" - Release amd64+mac (20130424) SourcePackage: deja-dup UpgradeStatus: Upgraded to xenial on 2016-04-22 (89 days ago) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/deja-dup/+bug/1605172/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp