A bug that has existed for much of 2018 for Windows 7 and Windows 2008 R2 has once again begun causing problems for users of those operating system versions.
The original bug forced many to reinstall hardware drivers for their network cards…
After you apply this update, the network interface controller may stop working on some client software configurations. This occurs because of an issue related to a missing file, oem<number>.inf. The exact problematic configurations are currently unknown.
To locate the network device, launch devmgmt.msc. It may appear under Other Devices.
To automatically rediscover the NIC and install drivers, select Scan for Hardware Changes from the Action menu.
Alternatively, install the drivers for the network device by right-clicking the device and choosing Update. Then choose Search automatically for updated driver software or Browse my computer for driver software.
UPDATE: The following is now resolved with KB4487345.
However, a new wrinkle may have been exposed in that network shares are no longer accessible using SMBv2.
The problem is exhibited in both KB4480960 and KB4480970.
A workaround has been offered that requires modifying the Windows registry – proper rights are needed to make the change:
reg add HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\system /v LocalAccountTokenFilterPolicy /t REG_DWORD /d 1 /f
A reboot is required.
You can also just remove the update, but this security patch is pretty critical to install.