Error on ADSAccount Insert : "There is no such object on the server"

Hello all,

I'm working on One Identity Manager On Demand v.9.2.

I've successfully created the Active Directory connector, done the initial synchronization of the Organizational Units and of some groups.

When I try to create a new AD user account through the assigning of account definition, it is correctly created in ADSAccount table under the correct ADSContainer (in this case is the OU = Unallocated User), but when it tries to insert it in Active Directory, I receive the following error: 

[1777018] Error running synchronization project (Active Directory Domain)'s workflow (Provisioning).
[1777124] Error running synchronization step (user) of synchronization configuration (Provisioning (Provisioning)).
[1777004] Method (Insert object (Insert)) could not be run successfully.
[System.DirectoryServices.DirectoryServicesCOMException] There is no such object on the server.

The organizational unit has been obtained from AD synch, and I can see it through a browse on Target System.

Some suggestions about it?

Thank you in advance,

Miriam.