---
name: reference_aadconnect_keycredlink_writeback
description: Diagnose/fix AAD Connect "completed-export-errors" — msDS-KeyCredentialLink writeback (8344 INSUFF_ACCESS_RIGHTS) blocked by AdminSDHolder on protected accounts
metadata:
  type: reference
---

AAD/Entra Connect AD-connector Export shows **completed-export-errors** every cycle while
AAD export + imports + sync all succeed, and one privileged account (Domain/Enterprise/Schema
Admins, `adminCount=1`) won't update in the cloud → it's almost always the **msDS-KeyCredentialLink
writeback** (Windows Hello for Business / passwordless key) being **denied by AdminSDHolder**.
The connector account (`MSOL_xxxx`) has key-writeback rights inherited on the OU, but SDProp
strips inheritance on protected objects → LDAP error **8344 / problem 4003 INSUFF_ACCESS_RIGHTS
{ msDS-KeyCredentialLink }**.

**Diagnose (all read-only, run on the Connect server; it's often the DC):**
- `Get-ADSyncScheduler` (rule out StagingModeEnabled), `Get-Service ADSync`
- `Get-ADSyncRunProfileResult -ConnectorId <id> -NumberRequested 8 | select RunProfileName,Result,StartDate`
  — note WHICH connector errors (AD = writeback, not the AAD/cloud direction). NOTE: `-RunProfileName`
  param and `.RunStepResults` detail are NOT available on older builds; event log id 6100 only gives counts.
- Real error detail comes from **csexport errors-only**:
  `& "$env:ProgramFiles\Microsoft Azure AD Sync\Bin\csexport.exe" "<AD-connector-name>" out.xml /f:x`
  then read `//cs-object` → `export-errordetail/@error-type` + `cd-error/error-literal` + the failing attr.

**Fix (grant the one attribute on AdminSDHolder so SDProp propagates to all protected accounts):**
```
dsacls "CN=AdminSDHolder,CN=System,DC=<dom>,DC=com" /G "<NETBIOS>\MSOL_xxxx:WP;msDS-KeyCredentialLink"
# force SDProp now: rootDSE RunProtectAdminGroupsTask=1 ; then Start-ADSyncSyncCycle -PolicyType Delta
```
`dsacls /G` is additive (one attribute-scoped ACE, removes nothing). Verify ACE landed:
`dsacls "<protected-user-DN>"` shows `Allow <dom>\MSOL_xxxx SPECIAL ACCESS for msDS-KeyCredentialLink`,
then csexport `/f:x` returns **0 errored cs-objects** and the next AD Export = success.

Same fault hits OTHER writeback attributes the same way — any attribute AAD Connect writes back to
a protected on-prem object. Confirmed attributes: **msDS-KeyCredentialLink** (WHfB/passwordless key)
and **msExchSafeSendersHash** (Exchange hybrid safe-senders writeback). Fix is identical; just swap
the attribute name in the dsacls grant. A persistent single-object `completed-export-errors` on the
AD connector with `permission-issue`/8344 on a Domain/Enterprise/Schema-Admin account = this pattern.

Instances fixed (all via /rmm as SYSTEM on the client DC — RMM agent on the Entra Connect box):
- 2026-06-16 **RUSSO-SRV** (Russo Law, rrs-law.com) — `guru@rrs-law.com`, msDS-KeyCredentialLink,
  since 2025-05-07 (17.7k retries). The Microsoft "sync error" email = Entra Connect Health flagging it.
- 2026-06-16 **GTI-INV-DC** (Glaztech, glaztech.com — Connect is on GTI-INV-DC not DC1) — `seastman`
  (Steve Eastman, their IT lead), msExchSafeSendersHash, since 2025-08-28 (13.9k retries).

NOT this pattern (different fix): a cloud-side `onPremisesProvisioningErrors` PropertyConflict
(duplicate UPN/proxyAddress) — that's a directory data collision needing a who-owns-the-address
decision, not a permission grant. (Glaztech also had one: CAS@glaztech.com on both the `CAS` user's
UPN and an alias on `alex` → CAS1944 parked on onmicrosoft UPN.) Related: [[reference_gururmm]].
