Over the week, Microsoft released a series of useful updates for all supported versions of Windowsas part of the company's "Patch Tuesday." For those who don't know, "Patch Tuesday" is an unofficial term from Microsoft that refers to the release of frequent security updates for the company's software products.
More specifically, the upgrades brought some known issues, but it seems that the company managed to handle the problem before it was released publicly.
According to a large number of reports on Reddit and Microsoft's TechNet forums, the KB4480970 security update for Windows 7 and Windows Server 2008 R2 with Service Pack 1 breaks access to SMBv2 shares once installed on the host. On the other hand, customers using Windows Server 2008 Service Pack 2 are experiencing similar issues with the corresponding monthly rollup KB4480968. It should also be noted that remote desktop access may not be possible for users whose accounts remain in the "Administrators" group on target machines after the upgrade.
For now, the easiest solution may be to simply uninstall the latest update, which seems to have fixed the issue for those who have reported it. If any user feels they can edit the registry on their computer, they can check out the German forums at administrator.de, where a workaround has been posted. Of course, editing the registry carries some risks, so make sure you have a backup before proceeding. To resolve the issues, type the following command in a Command Prompt window with administrator privileges on the host computer.
reg add HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\system /v LocalAccountTokenFilterPolicy /t REG_DWORD /d 1 /f
However, Microsoft does not seem to have acknowledged this issue, as it did not add a list of known issues. We hope that the company will fix the problem soon.
