I have installed dirsync and got it to sync once then it failed and I was told to run the wizard again.
I ran the wizard and it failed due to an issue with SSO. I fixed SSO, which works fine now, but dirsync fails with an error of "A constraint violation has occurred" and in the event log the only thing showing is a warning about the MSOL_AD_Sync password reset.
The account is in the root domain and the accounts I have tried to run the wizard with for the domain are both Enterprise admins and Domain admins and have full control to both the OU and the MSOL_AD_Sync account. There are no deny permissions on any of those accounts. All attempted accounts are also a member of the local admin and the dirsync local account.
I have uninstalled about 10 times and reinstalled with a reboot between each one.
I have been unable to find any helpful info on the web for even coming close to what the issue is. Not sure why if it worked once it wouldn't work again.