Symptoms
After you install the Windows 10 Technical Preview build 9879, a black or blank lock screen prevents you from logging on to Windows. When this problem occurs, the computer does not respond to keyboard or swipe actions.
Cause
This problem occurs because of a change in the behavior of WinLogon and LogonUI. This change introduces the potential for the deadlock.
Resolution
An update is available to resolve this problem.
How to obtain and install this update
Windows Update
Use Windows Update to automatically download and install the update.
Prerequisites
To apply this update, you must have Windows 10 Technical Preview build 9879 installed.
Registry information
To apply this update, you do not have to make any changes to the registry.
Restart requirements
You must restart your computer after you install this update.
File information
This update contains the files that are listed in the following table.
| File name | File version | File size | Date | Time | Hashes |
|---|---|---|---|---|---|
| Authui-ppdlic.xrm-ms | Not applicable | 2,894 | 08-Nov-2014 | 11:30 | Not applicable |
| Authui.dll | 6.4.9879.2 | 2,473,472 | 08-Nov-2014 | 10:08 | MD5: 6FB773CE32A5B1F8F0CB5E8C07A13946 SHA1: 876AA0C92FE7503240A36E8401307BE3AEB9D1D9 |
| Actxprxy.dll | 6.4.9879.2 | 4,164,608 | 08-Nov-2014 | 10:08 | MD5: 44F9C4F4E0D31B9F3EE0AAD73ADB6630 SHA1: A9F4AB399CCD5B186F74DDADEB385F79E94ADE31 |
| Logonui.exe | 6.4.9879.2 | 13,824 | 08-Nov-2014 | 10:09 | MD5: 8DD38771E7A783C35AF3E30A7022A40C SHA1: 357A4543175D28AEEFB3D35BA0C77BBF9866ED6B |
| Authext.dll | 6.4.9879.2 | 71,680 | 08-Nov-2014 | 10:08 | MD5: 2EF729E2D4BC9A0DAF292DC6AA9BCEFC SHA1: C63E32B0DC57DC97634BDD75B48E0B12A281F94A |
| Logoncontroller.dll | 6.4.9879.2 | 401,920 | 08-Nov-2014 | 10:09 | MD5: 71DACF2BA1F0B66D9B2F7B3B1B347B80 SHA1: 282D0D0D9E95327A6944678D1B7D4FEE902581F0 |
| Pdc-mw.ptxml | Not applicable | 4,531 | 08-Nov-2014 | 04:33 | Not applicable |
| Pdc.sys | 6.4.9879.2 | 85,024 | 08-Nov-2014 | 11:29 | MD5: 7D0BD069F6804B38771638D63EA40181 SHA1: DF69BB70039A4ABF29D78031971A25F2C7B157FD |
| Shcore.dll | 6.4.9879.2 | 688,192 | 08-Nov-2014 | 11:31 | MD5: 316E350487F43B33C3F3CB6A2759DA41 SHA1: F7E19B03B7E58FBB2FD31D1B787165D62D9FBB58 |
| @tileempty1x1image.png | Not applicable | 120 | 05-May-2014 | 05:57 | Not applicable |
| Twinui.dll | 6.4.9879.2 | 14,028,800 | 08-Nov-2014 | 10:09 | MD5: 17D2A53121F47D9040BB7C06CB2F08A5 SHA1: 0D7AC0290682B0909E4ECFCB350576FB93E81430 |
| Windows.systemtoast.autoplay.lnk | Not applicable | 1,454 | 08-Nov-2014 | 04:32 | Not applicable |
| Windows.systemtoast.devices.lnk | Not applicable | 1,446 | 08-Nov-2014 | 04:32 | Not applicable |
| Windows.systemtoast.share.lnk | Not applicable | 1,547 | 08-Nov-2014 | 04:32 | Not applicable |
| Usercpl.dll | 6.4.9879.2 | 1,306,624 | 08-Nov-2014 | 10:09 | MD5: D091E39A70135371492DC074EA5B2DEB SHA1: 6AB6E8D587488D9A7E3D120D3065DF61D9790C3E |
| Usercpl.ptxml | Not applicable | 789 | 08-Nov-2014 | 04:34 | Not applicable |
| Wininitext.dll | 6.4.9879.2 | 32,288 | 08-Nov-2014 | 11:34 | MD5: 6E6BA516A119AD49B0E8280D909B3CEB SHA1: 9481A5DF68384EAC1FDE61672346490A790FA1F7 |
| Wininit.exe | 6.4.9879.2 | 225,408 | 08-Nov-2014 | 11:34 | MD5: C76B88310712E3F3AB7F250F7750C782 SHA1: 45C5055EFE1A8C9E700515203D9598AC4A709BA2 |
| Wmsgapi.dll | 6.4.9879.2 | 16,896 | 08-Nov-2014 | 10:09 | MD5: 16D9CF51544197E74E59740410C213C6 SHA1: B455B28D1D8B3579EFC96D6BEB4D228D86BFF00A |
| Winlogon.exe | 6.4.9879.2 | 550,400 | 08-Nov-2014 | 10:09 | MD5: 5811886282186EEEFAAE6D1B224C0115 SHA1: 7E5621EC78381E43936070823A465B26A1A838AF |
| @tileempty1x1image.png | Not applicable | 120 | 30-Jul-2014 | 23:19 | Not applicable |
| Twinui.dll | 6.4.9879.2 | 12,641,280 | 08-Nov-2014 | 09:11 | MD5: F791AD77ACFC4C99FA8D493AAE44EB7E SHA1: E1D1B1641B0EAEC37BD84D462B308BF4D1E9BF2C |
| Wmsgapi.dll | 6.4.9879.2 | 13,312 | 08-Nov-2014 | 09:11 | MD5: DA2CD91B467D2FFD14FA6AFC4D893456 SHA1: 093FF2B0E348790A7C133562890FE7E464C1814D |
| Authui-ppdlic.xrm-ms | Not applicable | 2,894 | 08-Nov-2014 | 09:29 | Not applicable |
| Authui.dll | 6.4.9879.2 | 2,223,616 | 08-Nov-2014 | 09:11 | MD5: BA507C9A06281684EB539806A4FAA3A9 SHA1: F4E8B838ABAF38B2B9DD243C0B0E1B82E4BBE6FB |
| Actxprxy.dll | 6.4.9879.2 | 1,583,104 | 08-Nov-2014 | 09:11 | MD5: E3F551449DC84441F8DFB29FFE3B526F SHA1: C74B7F273B680B02B2FE502ADEB27A29BE028356 |
| Authext.dll | 6.4.9879.2 | 59,392 | 08-Nov-2014 | 09:11 | MD5: 3C62AE6BEE735BA161BA10CA6E40C9AB SHA1: C465F273ECF81A04CB81E90EAB2416AB6BC19B8E |
| Logoncontroller.dll | 6.4.9879.2 | 316,416 | 08-Nov-2014 | 09:11 | MD5: 9A144E7904D1961D382D95098DF1D43E SHA1: 61E57A54495EC628FC776B0ACF62625D83F241ED |
| Shcore.dll | 6.4.9879.2 | 544,632 | 08-Nov-2014 | 09:34 | MD5: 5AF92E28A1BEF5E6038712965E43BC9D SHA1: A763080BB04F4A075765CE1134C1A47C418D7600 |
| Usercpl.dll | 6.4.9879.2 | 1,222,144 | 08-Nov-2014 | 09:11 | MD5: 9260E275CE08B068BBFA2C3746D7F48D SHA1: 531AB1F771785944DE8F60CCF2F16222291CA1EB |
| Usercpl.ptxml | Not applicable | 789 | 08-Nov-2014 | 04:35 | Not applicable |
| Wininitext.dll | 6.4.9879.2 | 27,160 | 08-Nov-2014 | 09:37 | MD5: DA92F510A5BBD5543ECC5A2C2E7A194B SHA1: 4709E8E03D052CECD67A0A10DEA988D82820659D |
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.