It is well known that Microsoft is pushing as hard as it can to force users to move to the revamping OS Windows 10. But this time they went too far.
Yesterday, January 9, 2019 Microsoft released a security (important) update, KB4480970 for Windows 7 enviroment. Windows 7 environment also include Server 2008 R2.
Such update, far from fixing problems, caused a mayor issue to Server Message Block (SMBv2) protocol. The Server Message Block (SMB) is a network file sharing protocol. It is a client-server implementation and consists of a set of data packets, each containing a request sent by the client or a response sent by the server.
Once this update is applied the client computers will not be able to access the server sharing the files through a UNC path (Universal Naming Convention) and leaves users receiving an INVALID_HANDLE when attempting to kick off a SMB2 connection. You will not be able to access either by host name neither by IP.
The problem is related to Microsoft tweaking security settings in the update, with administrators on the host system being affected.
Microsoft has not respond to this issue yet.
Meanwhile the work around of it is to applie the following registry as administrator or uninstall the damaged update:
reg add HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\system /v LocalAccountTokenFilterPolicy /t REG_DWORD /d 1 /f
In our case, we have been able to go to the installed Updates and removed the offensive updates and once the server or PC hosting the files rebooted everything works fine.
This is a shame on Microsoft who wants to force all users to move to Windows 10.
Our recommendation is to try, as far as possible, to upgrade your windows devices to Windows 10 base.
We understand the situation of it, but it is not easy keep fighting against a giant like Microsoft is. In top of that if you business is required to comply with extended security like HIPAA or any other kind of personal information protection you want to do the update to avoid headaches in the future.
Contact your software vendor or your IT guys to do the proper research for Windows 10 compatibility and update to Windows 10 as soon as possible.
It could cost you more in repairs that in the upgrades.