Update to the DirSync Logon failure post

DirSync Logon failure

I initially posted about re-installing DirSync to fix the login service issue for the Forefront Identity Manager Synchronization Service. While that fixed it initially I found further updates and reboots still caused the service to fail to start. I even installed the new Microsoft Azure Active Directory Sync Services tool and that looked like it fixed it for awhile, but it to fell into the reboot/update issues eventually.

To skip to the final fix it seems like it was to do with a GPO setting in the end. The fix was to enable the local AAD account DirSync creates into the Log on as a service GPO.

Some articles say to edit the local policy on the DirSync server, but I had to do it on the DC as I had a GPO that was overwriting that local machines policies (it will be greyed out).

Computer Configuration –> Windows Setting –> Security Settings -> Local Policies / User Rights Management

Edit Log on as a service and add the account.

After restarting the machine or applying the GPO /Force the service would now start.