After installing KB4503267, KB4503294, or KB4503288, you may experience issues with connecting to SAN storage and have event logs filled up with Event ID 43 from iScsiPrt and a description of “Target failed to respond in time for a login request”. A fix for this is now available by installing KB4509475. An immediate workaround is a reboot of the server.

https://support.microsoft.com/en-gb/help/4509475/windows-10-update-kb4509475