#11 Could not load type

[AYMAN KROSH]

Hi
I installed the from this URL
http://sourceforge.net/projects/tustena/files/Tustena%20CRM%203.9%20OS/Tustena%20CRM%203.9%20OS%20Pre/TustenaOS3.9pre.zip/download
and I execute the database_os_39.sql script.
And I fixed the connection string

When I start the application , I face this two error:
1. Error 70 Could not load type 'Digita.Tustena.FreeFileds?'..... \os\Admin\FreeFields?.aspx 3
2. Error 71 Could not load type 'Digita.Tustena.Liste'. .....\os\Admin\Lists.aspx 2
Can you help me please

With a lot of thanks