SMBv1 file sharing over NetBIOS broken

This out-of-band update, released to fix Office and App-V crashes, carried forward a bug from September’s Patch Tuesday that broke SMBv1 file sharing over NetBIOS. Legacy NAS devices and older servers using SMBv1 via NetBIOS became inaccessible — shared files and folders simply vanished from the network. Microsoft’s workaround was to force SMB over TCP port 445 instead, which is essentially telling users to stop using the protocol Microsoft broke. Yes, SMBv1 is deprecated. No, that doesn’t help the countless small businesses still running decade-old NAS boxes that only speak SMBv1.