Windows 8.1 - Can't access share on Mac with valid credentials

SideStepSociety

macrumors 6502
Original poster
Feb 12, 2011
362
11
Vancouver, BC
The title pretty well says it all.

I can see my Mac mini Server in Windows browser, ping my IP, etc, etc. I am also able to log in as Guest and get access to the Public folder.

However, I am unable to log in with any valid user accounts and credentials. Created a new, temporary test account and was also unable to access with that.

Anyone have any thoughts?
 

Gorazd

macrumors newbie
Oct 23, 2014
5
1
Hi,

run regedit.exe as administrator on the Win 8.1 machine.

Delete this DWORD line in the Win 8.1 registry and you shall be fine:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa\LmCompatibilityLevel

You do not need to restart the Win 8.1 system in order that you can now successfully connect
for example to the: \\MACMINI\HARDDRIVESHARE from Win 8.1 machine.

You only need to fill the administrator name and password login for the Mac OSX computer
and you shall now successfully map the Mac network drive on the Win 8.1 machine.

Best regards,

Gorazd.
 
Last edited:

SideStepSociety

macrumors 6502
Original poster
Feb 12, 2011
362
11
Vancouver, BC
That did it! Thanks Gorazd.

Edit to add: Might be worth noting that the default value for this key is 3, and I got the same result by changing it to 3 from 2. Also, there's a small typo in your registry location. Should be:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa\LmCompatibilityLevel
 

cricrimi

macrumors newbie
Jan 28, 2007
5
0
same with xp and yosemite

Hi all,

I have an imac hooked up on my network as well as an ultrasound machine (running xp in some form), both visible on the network.

Up until mavericks, I had a shared folder on my imac to which I could back up ultrasound picks directly from the ultrasound machine with user/pswd credentials. It worked through all my upgrades from Mountain lion through snow leopard and mavericks.

But not with Yosemite: The ultrasound machine only gets a login failed, unknown user name/bad password reply although nothing has changed.

I can only link the bug to yosemite but aside from making sure all the sharing options are correct, am stuck!

Really need this link for medical purposes

Thanks for any insight!!

Chris
 

chucktowndcroz

macrumors newbie
Dec 16, 2015
1
0
Hi,

run regedit.exe as administrator on the Win 8.1 machine.

Delete this DWORD line in the Win 8.1 registry and you shall be fine:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa\LmCompatibilityLevel

You do not need to restart the Win 8.1 system in order that you can now successfully connect
for example to the: \\MACMINI\HARDDRIVESHARE from Win 8.1 machine.

You only need to fill the administrator name and password login for the Mac OSX computer
and you shall now successfully map the Mac network drive on the Win 8.1 machine.

Best regards,

Gorazd.

OMG SO MUCH RESEARCH! THANK YOU SO MUCH. I made an account just to say thank you
 

LoneBoneman

macrumors newbie
Mar 16, 2018
2
0
OMG SO MUCH RESEARCH! THANK YOU SO MUCH. I made an account just to say thank you
Does this work with Windows 10 network? Hesitate to mess with registry and create other problems. I have been trying all kinds of "fixes" for this issue which seemed to appear rather recently. Nothing seems to work. My wife and I are on the same home network and same Workgroup. I can see the Mac, but cannot access it to be able to access files. She can however access my windows 10 computer (and obviously see it as well).
 

LoneBoneman

macrumors newbie
Mar 16, 2018
2
0
Hi,

run regedit.exe as administrator on the Win 8.1 machine.

Delete this DWORD line in the Win 8.1 registry and you shall be fine:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa\LmCompatibilityLevel

You do not need to restart the Win 8.1 system in order that you can now successfully connect
for example to the: \\MACMINI\HARDDRIVESHARE from Win 8.1 machine.

You only need to fill the administrator name and password login for the Mac OSX computer
and you shall now successfully map the Mac network drive on the Win 8.1 machine.

Best regards,

Gorazd.
I have the same issue with windows 10. Started mysteriously on it's own as I made no changes to anything. Able to see Mac on the network, but unable to access anything. Inconvenient to attach files to emails when all computers are in the same house. The DWORD is set to 1. Should it be 3 or delete entirely?

I tried the following and it worked immediately. Perhaps before messing with the registry, give it a try first:

"OSX will ONLY accept LAN network authentication level 2 responses only. Windows default for this value is not set.

To fix this go to on the Windows side: Control Panel > Administrative Tools > Local Security Policy > Local Policies (on left panel) > Security Options >

"Network Security: LAN Manager Authentication Level" > Set this to "Send NTLMv2 responses only"


https://www.reddit.com/r/osx/comments/3r5q16/cant_access_my_mac_from_windows_10/
 
Last edited:

renarde3

macrumors newbie
Jul 16, 2019
1
2
Gorazd and LoneBoneman, I can't thank you enough for pointing me in the right direction for a solution to my own Samba and Windows file sharing problems!

To help anyone who might stumble on this thread in the future, this was my situation.
My boyfriend and I started out with 7 computers on our home network including:
  • 1 Arch Linux NAS
  • 1 Arch Linux laptop
  • 1 Ancient XP laptop
  • 2 Windows 7 Pro laptops
  • 1 Windows Pro desktop
  • 1 Windows 10 desktop

We both work in IT and don't believe in throwing out old systems. We just re-purpose them and put them into semi-retirement. They were all happily sharing files back and forth as needed.

The problems started when we got a 2012 Mac Mini to serve as the controller for a massive backup drive.
All of the machines could see the SMB (Samba) share we created *except* for the XP laptop and the Win7 Pro desktop. Since the SMB share was created to house the backups of the various machines, they *all* have to be able to read and write to it. Failure was not an option. It was clearly a problem on the two machines that couldn't connect to the Backups share because 5 of the 7 computers were connecting just fine.

My partner and I must have spent 18 hours trying to find the fix. We tried all of these things and more:
1) Deleted and recreated the network profile on the Mac Mini at least half a dozen times trying to force the correct NetBIOS and Workgroup values to persist. That didn't work because of an old bug in the MacOS version of Samba.
Fun fact - We finally had to open a terminal window on the Mac Mini and do the following to force the NetBIOS profile settings to persist (good thing MacOS is essentially Linux):
$> sudo vi /Library/Preferences/SystemConfiguration/preferences.plist
Look for the "<key>NetBIOSName</key>" entry
Remove or update all of the NetBIOS name entries to suit your needs
$> sudo Killall -9 cfprefsd
reboot the Mac
2) Made around a dozen registry changes having to do with network compatibility between the two machines
3) Made around a dozen group policy changes having to do with network compatibility
4) Setup a NetBIOS / WINS server (using NMBD in Samba) on the Arch Linux NAS
5) Changed the IP address of the Mac Mini
6) Changed the hostname of the Mac Mini
7) Bypassed the hostnames by trying to map the Backups share using the IP address of the Mac Mini
8) Added entries to the /etc/hosts file on the Mac Mini for each of the computers that were trying to connect to the Mac Mini.

And none of that worked.

What finally worked for both the ancient XP laptop and the very old Win7 desktop (which was upgraded from XP) was a combination of your two suggestions:
1) Making this change in Windows Control Panel > Administrative Tools > Local Security Policy > Local Policies (on left panel) > Security Options >
"Network Security: LAN Manager Authentication Level" > Set this to "Send NTLMv2 responses only"
2) Running regedit.exe
3) Navigating to
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa\LmCompatibilityLevel
3) Modifying the DWORD value from 0 to 3
4) Rebooting the machine

Joy of joys, now all of the machines can backup to the new share.

And it wouldn't have been possible without your guidance! Thanks so much for posting what worked for you or we might still be trying to fix it!