Windows 10 with SMB1 enabled can't connect to New 3DS microSD card management anymore (error code 0x80070035)

[GameKillCard]

Windows 10 (I'm using IoT LTSC 2021) with the (old, and insecure, I know) SMB 1 protocol enabled is unable to connect to both my New 3DS and New 3DS XL. It finds the consoles on the network without any problems, but it is unable to connect. The error code it gives is 0x80070035. Has anyone else encountered this error and has been able to resolve it? Perhaps a recent Windows 10 update has broken compatibility in some way? Until a few months ago, it worked perfectly.

 

[Kwyjor]

I'd be very surprised if you find someone else in the same boat. I also wouldn't be surprised if a Windows 10 update was responsible.

Has anyone told you about using an old version of mucommander instead? (You'll need 1.0 or older.)
https://github.com/mucommander/mucommander/releases/tag/1.0.0-1

 

[GameKillCard]

I'd be very surprised if you find someone else in the same boat. I also wouldn't be surprised if a Windows 10 update was responsible.

Has anyone told you about using an old version of mucommander instead? (You'll need 1.0 or older.)
https://github.com/mucommander/mucommander/releases/tag/1.0.0-1

Thank you for your suggestion. I'll try to use mucommander. However, I discovered that this is something Microsoft has messed up recently on an OS level. In particular, it seems it's the September 9, 2025—KB5065429 update that has broken it.

As part of the Windows updates released on and after September 9, 2025, this update enables support for IT administrators to deploy hardening measures for SMB.

Known issues in this update
SMBv1 protocol connectivity

Symptoms

After installing the Windows update released on or after September 9, 2025, you might fail to connect to shared files and folders using the Server Message Block (SMB) v1 protocol on NetBIOS over TCP/IP (NetBT). This issue can occur if either the SMB client or the SMB server has the September 2025 security update installed.


Note: The SMBv1 protocol is deprecated and no longer installed by default in modern versions of Windows and Windows Server. Deployments that use newer versions of the protocol, SMBv2 or SMBv3, are not affected by this problem.

Workaround
This issue is resolved in Windows updates released on and after September 25, 2025 (KB5066198). We recommend you install the latest Windows update for your device as it contains important improvements and issue resolutions, including this one.

Although Microsoft says it has fixed this issue, this is not the case with my 3DS.

I have also tried connecting using Samba on Windows Subsystem for Linux (Ubuntu), which I understand ends up using the Windows configuration, and the result is the same.

Welp, it's a pity because FTPd works terrible for me. And I really hate removing the covers from my 3DS because I think I'm going to damage or scratch them at any moment.

I'm going to try with a Linux distro since Windows won't let me uninstall the update anymore.

While I continue testing things, could some kind soul check if, in their version of Windows, whether it's 11 or the 10 version for home users, and after enabling SMBv1 protocol, it works for them? Perhaps Microsoft has indeed fixed it in versions other than mine (IoT LTSC 2021).

 

[Kwyjor]

I forgot to add that I'm not sure where to find a binary for that old version of mucommander; if you happen to stumble across it, perhaps you could post it here. Sounds like less trouble than messing with a Linux distro.

Welp, it's a pity because FTPd works terrible for me.

Some users report having better luck with 3DShell.

 

[lisko]

What problems have you with ftpd? Try the last 3.2.1 CIA. I use it a lot and I haven't found a problem whereas the older versions had some little problems from time to time.