Cannot login as admin during installation

[luc]

After installing plesk, I logged in and started the setup. Before inserting the license I loss the internet connection.
Now when I log in again, the system after showing me the panel for less than one second, brings me back to the login page.
It's not a credential error.
ANy tips?
Thanks

 

[luc]

I tryed to install the trial license key trough ssh using the license command with no success : ./license -i /tmp/pp10key.xml
error: ./license -i : no such file or directory