SMB sharing not working after windows 10 update Build 2004 update

File sharing can only work when you enable sharing settings correctly. Besides, you also have to share data in the right way. For that, follow these steps:

Step 1. Click "Start" > "Control Panel" > "Network and Sharing Center" > "Advanced sharing settings".

*Under Private (current profile), check "Turn on network discovery" and "Turn on file and printer sharing". Click "Save changes" to confirm.

                 To make sure the problem can be solved, allow File and Printer Sharing in Windows firewall settings.

Although still a problem for many people, I have found that restarting the service "Workstation" and associated dependencies clears the issue up until the next reboot. Not a permanent fix but it certainly helps with the loss productivity and headaches until Microsoft provides a permanent solution.

This works every time for me.

I'd be curious for a chime in from users how many this quickly serves as a workaround.

I encounter this challenge in different setups since years. I solved it in the past, but didn't made notes on solution - so again read a lot of guessing, see that, try that... 

Our Setup and Requirements

Clients: Windows 10 Pro, instructions also apply to Windows 10

NAS: Linux with Samba Shares, local users, Workgroup and NetBios. 

Guest or anonymous access is disabled. 

Workgroup = SAMEPCNASROUTER

Shares = //MAXIMUM-15-CHAR/*shared folder names* 

A. Use Office 365 accounts  

Devices joined Azure AD (no MDM).

Too small use case to integrate NAS with Azure AD, in effort and it requires additional Azure licenses on top of Office 365 Business plan. Therefore each user connects to NAS with their existing LAN user and pw. 

Problem: Can't see or access Shares with these users, using NAS user connect as

Login to NAS using local accounts with same WORKGROUP/ID/PW on NAS worked from scratch. See further treading how to test this yourself.

B. Drop SMB 1 and Update SMB Server on NAS

Windows SMB Client uses 3.11, 

https://docs.microsoft.com/en-us/windows-server/storage/file-server/file-server-smb-overview

Problem: This NAS serves us since 10 years, and no firmware update includes SMB 3.

Check SMB version, here output after upgrade of SMB . 

[insaneuser@maximum-15-char ~]#smb2status

smbd (samba daemon) Version 4.0.25

smbd (samba daemon) is running.

max protocol SMB 3 enabled.

Turn off Windows Features 'SMB 1.0/CIFS File Sharing Support'. SMB DIrect' and 'NFS Client'  (unchecked). 

1. Win + S >Turn Windows features on or off

C. Display NAS Host under Networks 

NAS Host under Networks on Navigation pane of Windows Explorer must be shown.  

Solution 

A. Windows Credential with NAS hostname

Use Windows Credential with NAS hostname instead of a domain.

1. Win + S >Windows Credentials
2. Add a Windows credential
3. Set NAS host in front of username

maximum-15-char\insaneuser

B. Enable SMB 3 on NAS

Recommended SMB Configuration:

[insaneuser@maximum-15-char ~]#vi /etc/config/smb.conf

[global]

workgroup = SAMEPCNASROUTER

netbios = MAXIMUM-15-CHAR

min protocol = SMB2_02

max protocol = SMB3_11

SMB3 Settings of QNAP and Synology :

https://www.synology.com/en-global/knowledgebase/DSM/help/DSM/AdminCenter/file_winmacnfs_win

https://www.qnap.com/en/how-to/tutorial/article/how-to-use-smb-3-0-in-qts-4-2

C. Open a Share

It is not enough to map a network drive to see host and share under Navigation Networks.

You must first open a share, manually or by script.

We created a link to a share to each user home and pinned this link to Windows Explorer navigation pane.

Check and Set these Windows Configurations 

RequireSecuritySignature 

Windows is unable to access SMB shares on a NAS when SMB signing is enabled - In setup above this is off - 0

https://www.qnap.com/en/how-to/faq/article/windows-is-unable-to-access-smb-shares-on-a-nas-when-smb-signing-is-enabled-requiresecuritysignature1-how-can-i-fix-this-problem/

https://docs.netapp.com/ontap-9/index.jsp?topic=%2Fcom.netapp.doc.cdot-famg-cifs%2FGUID-EE6C5170-7CF6-492C-83A6-9904AE247F21.html

AllowInsecureGuestAuth

Windows is unable to see shares of hosts or show fallback. if is guest authentication is disabled - In setup above this is off - 0

https://docs.microsoft.com/en-us/troubleshoot/windows-server/networking/guest-access-in-smb2-is-disabled-by-default

Further Reading  

Naming Windows Workgroups and Domains

https://www.lifewire.com/naming-windows-workgroups-818240

Enable Local Account Login on a Client joined Azure AD 

In order to create a local test user account, this must be first enabled. 

This is not needed for final solution: 

1. Win + S > Edit group policy
2. enable Enumerate local users on domain-joined computers

HKLM\Software\Policies\Microsoft\Windows\System!EnumerateLocalUsers 3. after testing disable this setting. If you want to keep local accounts, read security considerations of Local Accounts (MS Docs > Windows > Security Identity and access protection).

Tested Environment 

QNAP T-259 Pro+, QTS 4.2.6 (20200611), samba daemon) Version 4.0.25

Microsoft Windows 10 Pro 10.0.19041 Build 19041

Heve you removed, before to create the bash, the normal connection to shared drive?