Hi all, We have the following issue: Migrated from Samba NT-Style/Classic domain to Samba 4.5.1 (a little later 4.5.2) AD domain. Most Windows clients and member servers at OS level of Win7 or Server 2008R2 were fine, but on a few, although right after the migration, users were able to log on to these machines, after a day or two users were unable to unlock or log in to these machines. Event viewer registers Event ID 4 as referenced in technet here for each login/unlock attempt: https://technet.microsoft.com/en-us/library/cc733987(v=ws.10).aspx The template text in the article matches the event viewer message exactly. One interesting point is that %1 is the netbios/short hostname of the relevant machine and the target name %3 is the same as %1 apart from it's a different case. We had a power outage over the weekend, which lasted and today a number of machines of the same OS version have suffered the same problem. In this case they were left locked and could not be unlocked by the user, with the same Event ID in Event Viewer. In both cases if the member machine is rebooted, the problem goes away. Any ideas on this issue guys and gals? Cheers Alex -- This message is intended only for the addressee and may contain confidential information. Unless you are that person, you may not disclose its contents or use it in any way and are requested to delete the message along with any attachments and notify us immediately. This email is not intended to, nor should it be taken to, constitute advice. The information provided is correct to our knowledge & belief and must not be used as a substitute for obtaining tax, regulatory, investment, legal or any other appropriate advice. "Transact" is operated by Integrated Financial Arrangements Ltd. 29 Clement's Lane, London EC4N 7AE. Tel: (020) 7608 4900 Fax: (020) 7608 5300. (Registered office: as above; Registered in England and Wales under number: 3727592). Authorised and regulated by the Financial Conduct Authority (entered on the Financial Services Register; no. 190856).