No theme at all !

hi ,

we are migrating our Moodle from one server to another. I did a complete backup and a restore to the new server. But I have no theme at all when I acess to the website !

I activated all debug messages (under admin/settings.php) but I have no message.

I tried to purge the cache (with command line and under the page admin/purgecaches.php)

I tried selected different themes

I tried diffrent navigator

I even changed the config.php file with the ip adress

but still have the issue !

Any idea is welcome. thanks for your help.

Moodle: 2.6.1+ ; Mysql: 5.5.35 (the same in the old server)

Php: 5.5.3 (was 5.3.10) ; Apache: 2.4 (was 2.2)

OS: Ubuntu server 13.10 (was Ubuntu server 12.04)