Provisionning AD Error: [1777004]

Hello all, 

I'm facing an issue and I tried many different ways to solve this, but the problème still exists. 

The problem is: after creating a user from the web portal, the user is created, get the AD account by the AccountDef and all things are doing well. but in the Job queue, I have the AdHocProjection of the ADS_ADSAccount_Insert process which still in "FROZEN" status. and the error is :

[1777219] Error executing synchronization step (person)!
[1777004] Method (Insert object (Insert)) could not be executed successfully.
[System.ArgumentNullException] Value cannot be null.
Parameter name: exception

so the manager never received the email information(SamaccountName and Pwd) about the new user. 

please I need help to solve the problem. 

Thanks a lot.