My shared drives were inaccessible after updating my windows 10 to the latest “Windows 10 Fall Creators Update”.
Within the latest “Windows 10 Fall Creators Update” the Guest access in SMB2 is disabled by default.
You can change this setting within your group policy settings.
Right click the Windows Icon at the bottom left of the task bar, or select the windows key + r
Within the run box, type “gpedit.msc”
Within the local Group Policy Editor, select “Administrative Templates”
Select “Network”
Select ”Lanman Workstation”
Double click “Enable Insecure guest logons” option
Tick the “Enable” option
Select OK
If this did not work consider checking this registry key too:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanWorkstation\Parameters\AllowInsecureGuestAuth
It should be set to 1 for your case.
Note: By enabling insecure guest logons, this setting reduces the security of Windows clients. https://support.microsoft.com/en-us/help/4046019/guest-access-smb2-disabled-by-default-in-windows-10-server-2016