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.
