Error creating a user through a trust in graphic mode

Hi everyone,

I have installed an AD Forest for the use of an application, let's say app1.com. For security reasons, a one-way trust has been created between this forest and the forest hosting the accounts of the users' company (contoso.com), so contoso users have access to resources inapp1.com, but users and computers in app1.com do not have access to contoso.com resources. Also note that the subnet for the application is behind a firewall.

Then I wanted to use my personal admin account in contoso.com to manageapp1.com. The problem is I receive an error when I use Active Directory Users and Computers console in order to create a user account : "An error occurred. Contact your system administrator."

I have no problems managing groups and computer accounts. And once the user account is created by another way, I can modify or even deleted it.And furthermore, I can create the account using PowerShell ! I used this command line :

New-ADUser -name "TEST User" -Enabled $true -AccountPassword $password -Description "this is a test" -DisplayName "TEST User" -GivenName "User" -Surname "TEST" -SamAccountName "user01" -UserPrincipalName "user01@app1.com" -Path "OU=Users,OU=Application,DC=app1,DC=com"

Is this a bug ? An expected behavior through trust ?

I would be pleased to have a solution, or at least an explanation

thanks