Windows – Access to network share failed after latest Windows 10 cumulative patch KB3189866

network-sharesnetworkingwindows 10windows-10-v1607

My PC with Windows 10 has just received the cumulative update version 1607 (KB3189866).

After the reboot the "net use" command on a network share folder fails with the following error message: "A specified logon session does not exist. it may already have been terminated"

Same problem and error if I tried to insert the path in Run dialog.

enter image description here

Do you know what could be the cause and how to solve it?

Best Answer

I found the most conclusive evidence as to the symptom and cause here:

Basically, if an SMB server has any anonymous shares, it appears that the KB3189866 patch causes Windows not does not ask you for credentials and just fails. You can get a number of different error messages for this. In my case it was:

The error you may get is "\\SERVERNAME" is not accessible. You might not have 
permission to use this network resource. Contact the administrator of this server 
to find out if you have access permissions. A specified logon session does not 
exist. It may already have been terminated

There are two workarounds, either:

  1. Uninstall KB3189866 (useful for proving it is the cause)

OR

  1. Add credentials for that share into the Windows Credential Manager:

    a. Go to Control Panel -> User Accounts -> Manage Your Credentials -> Windows Credentials

    b. For each server you wish to access, add in an entry (using "Add a Windows credential") with:

    • Internet or network address: \\SERVERNAME
    • User name: guest
    • Password: guest
Related Question