Update problem from 9.319-5 to U2D Package 9.355 / 9.375-5 on SG105

Hi all

First post for me. I am about to upgrade my SG 105 from 9.319-5 to 9.4 Beta (9.355 or 9.373-5). I added first the beta 2 license key, then I uploaed the 9.355 package manually. I then trigger the upgrade, but  the upgrade fails and I see the following errors:

2016:03:11-15:19:17 edge auisys[7149]: Starting up2date package installation

2016:03:11-15:19:18 edge auisys[7149]: >=========================================================================
2016:03:11-15:19:18 edge auisys[7149]: Failed testing RPM installation (command: 'rpm --test -U --nodeps /var/up2date/sys-install/u2d-sys-9.350012/rpms/libnavlextensions-9.35-1.g109c0f2.rb4.i686.rpm')
2016:03:11-15:19:18 edge auisys[7149]:
2016:03:11-15:19:18 edge auisys[7149]: 1. Modules::Logging::msg:46() /</sbin/auisys.plx>Modules/Logging.pm
2016:03:11-15:19:18 edge auisys[7149]: 2. Modules::Auisys::Legacy::Systemstep::real_installation:1232() /</sbin/auisys.plx>Modules/Auisys/Legacy/Systemstep.pm
2016:03:11-15:19:18 edge auisys[7149]: 3. Modules::Auisys::Installer::Systemstep::install:227() /</sbin/auisys.plx>Modules/Auisys/Installer/Systemstep.pm
2016:03:11-15:19:18 edge auisys[7149]: 4. Modules::Auisys::Up2DatePackages::install:143() /</sbin/auisys.plx>Modules/Auisys/Up2DatePackages.pm
2016:03:11-15:19:18 edge auisys[7149]: 5. Modules::Auisys::QueueIterator::process_qfiles:81() /</sbin/auisys.plx>Modules/Auisys/QueueIterator.pm
2016:03:11-15:19:18 edge auisys[7149]: 6. main::main:300() auisys.pl
2016:03:11-15:19:18 edge auisys[7149]: 7. main::top-level:35() auisys.pl

Same error happens if I upload the 9.370024-375005 package.

Advice appreciated.

Thanks for reading,
- Maurice