3 hours ago, Frank1940 said:

Someone had a similiar problem and resolved it by doing a Windows reinstall using the method that preserves the installed user programs and data.

1 hour ago, JorgeB said:

In my experience, when a Windows PC has those kinds of issues, best bet is to reformat.

48 minutes ago, Zonediver said:

An "Inplace Upgrade" is faster and do the job as well...

I just reinstalled Windows 11 Pro 25H2 from a USB install drive created in early October. I told the install to preserve user files and applications. I told it to not download and install updates. OS Build shows 26200.6584

• Network discovery and file sharing is still on for Private networks and off for public

• Credential Manager has credentials for Unraid server by server name and IP address using the Unraid user "shares"

• SMB v1 remains disabled

• Enable insecure guest logins remains enabled but should not be used as I am connecting via the Unraid user name and password

The problem remains. I can now consistently connect to Unraid GUI/shares via IP address, but, not by server name.

I hope I don't have to go the reformat and reinstall programs route as I have a lot of installed programs. I do need to uninstall a bunch of them, but, would rather no do that in a forced format/reinstall. :(

Edited December 18, 2025Dec 18 by Hoopster

55 minutes ago, Hoopster said:

I can now consistently connect to Unraid GUI/shares via IP address, but, not by server name.

Look at your Router from the PC with the problem. There should a table of attached devices and you should be able find that server's IP address and what the Device Name is for that address.

Then look at the same info using one of those PC's without the issue.

This all just some ideas but trying to figure why that PC has an issue and the other two do not. (Many long years ago I made the remark that solving SMB problems was more like Witchcraft than Science. And I still believe that when cases like yours crop up!)

I am not completely sure what use Windows makes of that information but it seems to find a lot of stuff to populate the Network pane on Windows File Explorer. And the router would be the point where it is probably starting from.

23 minutes ago, Frank1940 said:

Look at your Router from the PC with the problem. There should a table of attached devices and you should be able find that server's IP address and what the Device Name is for that address.

Then look at the same info using one of those PC's without the issue.

Identical on both PCs. The connected devices table from the UniFi router shows the following from all connected devices:

MediaNAS has two connections; MediaNAS LAN1 is IP address 192.168.1.10 (the Unraid server) of course, the other connection, as the name says is the IPMI LAN and has IP address 192.168.1.12

Whoa! This is a big issue. You can't have two computers with the same name and below is the AI take on restrictions:

I would suspect that the only the characters up to the first space (a DISALLOWED character) are being used for the computer name. Everything after that is ignored! So yes, you can get there via the IP address but \\server_name has 50% chance of failing! (I suspect one of these is the management port for the server's motherboard.)

OH . One more thing, The eight bit is masked. so Windows sees MediaNAS the same name as medianas as is MEDIANAS. I just tried this and it is still as trues as it was in DOS-3.2! Everything is still treated as through it is all caps. (Which is how DOS-3.2 stored file names as you may remember.)

23 minutes ago, Frank1940 said:

(I suspect one of these is the management port for the server's motherboard.)

Correct.

I'll try changing the name and report back. It's just a name alias in UnifFi Network. This is not an actual computer name in Windows to which I can see the above quoted rules applying.

Still baffled why there were no problems up until four days ago and is still works fine on other PCs.

Edited December 18, 2025Dec 18 by Hoopster

27 minutes ago, Hoopster said:

I'll try changing the name and report back.

• Changed name to IMPI-BMC MediaNAS

• Rebooted Unraid server

• Restarted router

No change.

I saw that Unraid 7.2.3 had "Samba upgrades for time machine" so, I thought, what the heck, I'll give it a try. I also mucked around in the Windows hosts file for the first time in years and added an entry for MediaNAS. I then rebooted the PC and, voila, I could access the Unraid GUI in a browser by server name but still not in File Explorer other than with the IP Address.

Edited December 19, 2025Dec 19 by Hoopster

Did you reboot the Windows PC? Sorry, I missed where you did that.

Edited December 18, 2025Dec 18 by Frank1940

4 hours ago, Hoopster said:

The problem remains. I can now consistently connect to Unraid GUI/shares via IP address, but, not by server name.

Have you set an entry to the File "HOSTS" under Windows?

This is necessary to reach unraid over the name...

Edited December 19, 2025Dec 19 by Zonediver

7 minutes ago, Zonediver said:

Have you set an entry to the File "HOSTS" under Windows?

As mentioned above, I did modify hosts and that worked for a while in browser only. Several minutes later, the host became unreachable by name in URL and I had to return to IP address. Still stuck at IP address in browser and file explorer as the only way reliably connect to Unraid server or shares on this PC only.

1 hour ago, Hoopster said:

As mentioned above, I did modify hosts and that worked for a while in browser only. Several minutes later, the host became unreachable by name in URL and I had to return to IP address. Still stuck at IP address in browser and file explorer as the only way reliably connect to Unraid server or shares on this PC only.

When i use FireFox and put in "unraid/Main", Google comes up - so its not working for me too.

I use always the IP of my server.

So whats the purpose of using names, if the IP is working?

Also at my explorer - i use only the IP of my server - but i have two NICs, so i have to use the IP and nothing else...

@Frank1940 @Zonediver @JorgeB

Thank you for your many suggestions.

At long last I have identified the source of the problem and fixed it. I can't believe I did not spot this sooner.

Was it a big deal that I could only access the server and shares via IP address and not server name? No; however, I don't like unsolved mysteries and when this started happening four days ago and only on one machine, I had to figure it out!

• I opened a command prompt and pinged the server by IP address. Success.

• I pinged the server by name (medianas) and discovered that the reply was coming from the Tailscale network name for the PC on ts.net

• I checked Tailscale settings on the PC and discovered that it was still connected and was using Tailscale DNS which appends the Tailscale name to the server name

• I disabled Use Tailscale DNS settings (of course, I also could have just disconnected from Tailscale)

Now I can access the Unraid GUI and Unraid shares by server name in browser, Windows File Explorer and my third-party file explorer (Directory Opus). Of course, IP address continues to work without issue.

The two PCs from which I had no access problems are not connected to the Tailscale network so it was never an issue for them. I have no idea what changed four days ago on this PC as it was working before and it has been months since I did anything with Tailscale on this or any other PC.

Edited December 19, 2025Dec 19 by Hoopster

On 12/17/2025 at 8:25 PM, Hoopster said:

I started having access problems to Unraid public shares on one Windows 11 machine only

I had this problem on a windows 11 Pro PC I added to my work peer to peer network.

Block NTLM (LM, NTLM, NTLMv2)

This policy controls if the SMB client will block NTLM for remote connection authentication.

If you enable this policy setting, the SMB client won't use NTLM for remote connection authentication.

If you disable or do not configure this policy setting, the SMB client can still use NTLM.

=========

(1) To open it, press Win + R, type gpedit.msc, and press Enter (this was on my 11 Pro box, but isn't on my 10 Home box)

Computer Configuration > Administrative Templates > Network > Lanman Workstation.

setting: Block NTLM (LM, NTLM, NTLMv2)

set to: Disabled

Apply the changes and restart the computer or run gpupdate /force.

Note: Another way to do with is in Powershell: Set-SmbClientConfiguration -BlockNTLM $false

(2) you might have to do this first.

Enable SMB 1.0/CIFS Client: Go to Control Panel > Programs > Turn Windows features on or off. Check the box for "SMB 1.0/CIFS File Sharing Support" and restart.

Note: I added gpedit.msc to windows 10 home via this method. The Block NTLM policy was not present in Windows 10 Home.

1 hour ago, digitaldoctor said:

I had this problem on a windows 11 Pro PC I added to my work peer to peer network.

I had tried all of the things you mentioned before I discovered that on that PC only. I had SMB 1.0/CIFS disabled and wanted to keep it that way, but, that was not the problem. Tailscale was enabled on that machine and was messing with DNS names. I could get it to the point that IP address worked, but server name did not. Turning off Tailscale DNS on that machine did the trick.

SMB1 is disabled for a reason : it is now so bad for security.

9 hours ago, digitaldoctor said:

I had this problem on a windows 11 Pro PC I added to my work peer to peer network.

Block NTLM (LM, NTLM, NTLMv2)

This policy controls if the SMB client will block NTLM for remote connection authentication.

If you enable this policy setting, the SMB client won't use NTLM for remote connection authentication.

If you disable or do not configure this policy setting, the SMB client can still use NTLM.

=========

(1) To open it, press Win + R, type gpedit.msc, and press Enter (this was on my 11 Pro box, but isn't on my 10 Home box)

Computer Configuration > Administrative Templates > Network > Lanman Workstation.

setting: Block NTLM (LM, NTLM, NTLMv2)

set to: Disabled

Apply the changes and restart the computer or run gpupdate /force.

Note: Another way to do with is in Powershell: Set-SmbClientConfiguration -BlockNTLM $false

(2) you might have to do this first.

Enable SMB 1.0/CIFS Client: Go to Control Panel > Programs > Turn Windows features on or off. Check the box for "SMB 1.0/CIFS File Sharing Support" and restart.

Note: I added gpedit.msc to windows 10 home via this method. The Block NTLM policy was not present in Windows 10 Home.

I just checked on three Windows 11 PRO (25H2)— All that I had quick access to this morning —and none of them had 'Block NTLM (LM, NTLM, NTLMv2)' enabled.

It appears that using NTLM is a security hazard but turning it off on a client can cause problems as you have discovered. But after doing come googling, it appears to completely turn it off, one must first verify that is is not being used by any devices on the network. (MS has been trying to get rid of part of it since 2010 and I gather they are proceeding down that path on their server products. But that is an entirely different proposition to turning it off on a client computer. If the server allows (or requires) NTLM, why would one want to prohibit a client from using it? — Now, this is where the Corporate and Government IT security people get really involved...)

Do you know why it was enable on your particular client? Is it a brand new one, you just purchased? Is it an old refurnished corporate one?

23 hours ago, Frank1940 said:

Do you know why it was enable on your particular client? Is it a brand new one, you just purchased? Is it an old refurnished corporate one?

Interesting.

It was a second hand PC. Probably a corporate one.

Are you saying the Block NTLM setting was added as a desired part of a custom install of Windows 11 for the company that had this PC ?

I certainly wanted to post my Block NTLM issue as it took me all day to find and there was very little information about it on the internets.

On 1/6/2026 at 1:53 AM, ChatNoir said:

SMB1 is disabled for a reason : it is now so bad for security.

I am going to remove SMB1 soon.

I don't think it is needed after I got rid of the Block NTLM (LM, NTLM, NTLM2).

I think the peer to peer network will run on NTLM2.

3 minutes ago, digitaldoctor said:

Are you saying the Block NTLM setting was added as a desired part of a custom install of Windows 11 for the company that had this PC ?

That would be my assumption. Many corporations want to restrict the servers that they allow their 'road warriors' to be able to connect. Remember that these road warriors often use access points that are not secured and it is easier to put restrictions on the PC than to expect that a road warrior after a couple after-dinner drinks is going to exercise the best judgement! So they block any method of network access that is not required to get on their corporate network. (And, needless to say, they have already blocked any protocol that is not secure there!)

The refurbisher generally reinstalls the OS but who knows where they got the image from or what settings were already 'cooked' into it.

3 minutes ago, Frank1940 said:

The refurbisher generally reinstalls the OS

I'll ask them but I am reminded of the deteriorating Windows conditions. It's time for me to move away from it.

TPM, Secure Boot, almost forced MS account, Privacy nightmare. It really feels like Windows will be entirely cloud based soon and your PC will be a dumb terminal. I should have installed Tiny11 on this PC. Live and Learn.

13 hours ago, digitaldoctor said:

I am going to remove SMB1 soon.

I removed SMB1 and the setup still works.