Fix ERROR_DS_INSTALL_NO_SRC_SCH_VERSION (0X0000213F)

You're in the middle of promoting a new domain controller and DCPROMO throws ERROR_DS_INSTALL_NO_SRC_SCH_VERSION (0X0000213F). This almost always hits when you're adding a newer OS DC to an older forest, like trying to promote a Server 2008 R2 DC into a 2003-era environment. Or you're going the other way — old media, new forest — and the source domain's schema is newer than what the installation source supports.

The root cause is dead simple: the schema version on the source domain controller doesn't match what the DCPROMO source (typically a CD or an ISO) expects. Windows checks objectVersion in the schema partition before it copies anything. If the source has a higher version than the target, it refuses to proceed. It's a safety mechanism to prevent schema corruption. The culprit here is almost always a schema that's been extended by Exchange, System Center, or a half-baked third-party schema extension that bumped the version past what the installation media knows.

What You're Actually Looking At

Check the schema version on the source DC — the one you're copying from. You can do this with ADSI Edit or a simple PowerShell snippet:

Get-ADObject "CN=Schema,CN=Configuration,DC=yourdomain,DC=com" -Property objectVersion

On a Server 2003 forest, you'll see objectVersion of 30 or 31. Server 2008 bumps to 44, 2008 R2 to 47, and 2012+ goes higher. The error means your source has a version DCPROMO's source doesn't recognize — usually because the installation files are older than the source schema.

The Fix: Get Your Media and Schema in Sync

Here's the thing — you don't fix this by editing the registry or forcing a version. That way lies pain and a broken AD. The real fix is to use installation media that matches or exceeds the source schema version. But if you're stuck with older media, you've got two options.

Option 1: Upgrade Your Source Schema (Recommended)

If your source DC is older and you're trying to bring up a newer one, run adprep /forestprep and adprep /domainprep from the newer media on the source DC. That bumps the schema version to match the media you're using. For example, if you're adding a 2008 R2 DC to a 2003 forest, run adprep from the 2008 R2 installation disc on the schema master.

Log on to the schema master as a member of Schema Admins and Enterprise Admins.
Insert the newer Windows Server installation media.
Open an elevated command prompt and navigate to the \sources\adprep folder on the media.
Run adprep /forestprep and follow the prompts, then adprep /domainprep.
Wait for replication to complete, then rerun DCPROMO.

That's the clean fix. It'll take a few minutes, but it's the right way.

Option 2: Use Newer Media

If you can't run adprep — maybe you don't have the schema admin creds or the source is already beyond the media's capability — pop in the installation media that matches the source forest's version. That means if you're joining a 2008 R2 forest, use 2008 R2 media. If you're trying to install an older DC into a 2012 forest, stop. That's not supported anyway.

If It Still Fails

If you've run adprep and still see the error, check for a few things:

Replication hasn't caught up. Force replication with repadmin /syncall on the source and wait for the schema to replicate to all DCs.
Check the DCPROMO log at %systemroot%\debug\dcpromoui.log — it'll tell you exactly which DC it's reading from and the version it expects.
Verify you haven't got a stale schema master. If the schema master was transferred recently, the old one might still have an older version. Check with netdom query fsmo.

One last thing — don't bother with the registry hack to overwrite objectVersion. It'll let DCPROMO run, but you'll end up with a broken schema that'll bite you at the worst possible moment. I've seen this end careers. Do it right.