A few days ago Microsoft released a Cumulative Update for Windows 7 which caused a number of issues.
One of the issues with KB4480970 which slipped through testing was problems with accessing SMBv2 network shares. Microsoft (and many Windows 7 users) discovered the issue after its release, and Microsoft promised to release a fix later in the month.
It seems we did not have to wait too long, as KB4487345 is now here.
KB4487345 is an update for Windows 7 SP1 and Windows Server 2008 R2 and brings the following changes:
This update resolves the issue where local users who are part of the local “Administrators“ group may not be able to remotely access shares on Windows 7 SP1 and Windows Server 2008 R2 machines after installing the January 8th, 2019 security updates. This does not affect domain accounts in the local “Administrators” group
Windows 7 users can download the update by checking for updates or downloading the update from Microsoft’s Update Catalogue here.
via Tero Alhonen