The installation was succesful, post installation tasks went to the end, the XPO projects were imported in AX, synchronisation is done and you’re sysadmin on all SQL Server instances and local Administrator of Windows servers.

The .Net business connector can connect to the AX environment as I can view a worker process when you launch the IDMF console and there is no error in the event viewer on the server where IDMF is deployed.

The macro #define.SysAdministrator('System administrator') should have been defined as a multi language capable label instead of hard coded in US English

Solution:

Go to \Classes\DMTValidateAdminUser method: vaildate user

in Standard you find there:
#define.SysAdministrator('System administrator')

because this is a French Installation you have to replace this through :

#define.SysAdministrator('Administrateur Système')