Fix ERROR_DS_CONSTRAINT_VIOLATION 0x202F in AD

Quick Answer

Check the object's mandatory attributes—most often sAMAccountName is missing or malformed, or you're trying to place an object under a container that isn't an organizational unit (OU). Use ADSI Edit or PowerShell to inspect and fix.

I've seen this error pop up in all sorts of places: when a junior admin tries to create a user with a space in the logon name, when a script tries to move a computer to a built-in container, or when a legacy app attempts to set an attribute that's since been deactivated in the schema. The root cause is almost always a violation of a schema rule or an object's mandatory attribute. The schema defines what must be present, and the directory service enforces it like a strict teacher. If you miss a required attribute or set one to an invalid value, you get 0x202F.

Here's the fix, in the order I usually run it.

Fix Steps

1. Look at the exact operation that failed. Open Event Viewer, go to Windows Logs > Directory Service, and find the most recent error with ID 1207 or 1126. The detail usually says which object and which attribute caused the violation. Note it down.
2. Open ADSI Edit (run adsiedit.msc). Connect to the domain partition that contains the object. Find the object you were creating or modifying. Right-click > Properties, and check the mandatory attributes listed in the schema. The usual culprits are sAMAccountName, userPrincipalName, cn, and for users, objectCategory.
3. Fix the offending attribute. For example, if sAMAccountName is missing, set it to the logon name (no spaces, 20 chars max). If it's set to something like "John Doe", that'll fail. Also make sure userPrincipalName matches the domain (e.g., jdoe@contoso.com).
4. Check the parent container. You cannot create a user directly under a container like CN=Users—that's a container, not an OU. Users must go under an OU (e.g., OU=Employees). If you attempted to create under CN=Computers, that also fails. This is the #1 mistake I see from folks coming from a workgroup background. Move the object to a valid OU using Active Directory Users and Computers (ADUC) or PowerShell's Move-ADObject.
5. Retry the original operation. If the object was half-created, delete it first (if it shows up in ADUC), then re-run the creation script or wizard.

Alternative Fixes

If the above doesn't clear it, the problem might be a schema mismatch because of a lingering domain controller (DC) that hasn't replicated. Here's what to do:

• Force replication with repadmin /syncall /AdeP. Sometimes one DC has an older schema version and rejects the attribute. This often happens after you extend the schema for Exchange or Skype.
• Check for schema conflicts using repadmin /showattr on the object to compare across DCs. If you see inconsistent values, that's your culprit.
• If the attribute itself is deactivated (e.g., an old app tries to set userCertificate when the schema no longer allows it), you'll need to redeploy that app, not fight the schema. I wasted a day on a client's CRM trying to force a deprecated attribute—the vendor eventually confirmed it was dropped in the latest version.

Prevention Tip

The real prevention is to stop hand-creating objects. I force my clients to use a standardized PowerShell script for user creation, which validates all mandatory attributes before hitting AD. Here's a snippet that checks for the common gotchas:

Import-Module ActiveDirectory
$params = @{ Name = "John Doe"; GivenName = "John"; Surname = "Doe"; SamAccountName = "jdoe"; UserPrincipalName = "jdoe@contoso.com"; Path = "OU=Employees,DC=contoso,DC=com"; AccountPassword = (ConvertTo-SecureString "P@ssw0rd" -AsPlainText -Force); Enabled = $true }
New-ADUser @params -Verbose

Also, run Get-ADDomain | fl ForestMode, DomainMode to confirm you're on a functional level that matches your tools. If you're on 2008 functional level and trying to use features that need 2016+, you'll get weird errors like this. Keep the schema updated by running adprep /forestprep on an elevated DC before adding new servers.

In the end, 0x202F is a tell—it says you're not playing by AD's rules. Learn the schema basics and you'll dodge it. I've had to fix this for a manufacturing company whose entire HR onboarding script broke because they used a space in the sAMAccountName. Ten minutes with ADSI Edit saved them a day of downtime.