Archive for December, 2019

Notes To Myself: Fixing File Sharing in Windows 10 after “Fall Creators Update” breaks it

About 2 years ago, sharing movies from my desktop (Windows 10, alas) to the old Linux Mint laptop acting as a Chromecast-that-plays-local-content-without-weird-workarounds randomly stopped working, with Gigolo reporting the very helpful error, “Connection timed out”. Fair enough, it’s not Gigolo’s job to diagnose problems caused by dodgy Windows updates. After more Googling than it should have required (and 2 years putting it off for lack of computer-fixing and movie-watching time as the laptop, a horizontal surface, slowly drowned under new clutter), it turns out that some then-recent Windows updates, installed during the night for your convenience, silently break several features non-Windows hosts (yes, even recently updated ones) depend on to access Samba/CIFS shares.

One of these changes, beginning in version 1803, is to break the ability to discover shared folders or their hosts on the network via browsing. (You can still access them via UNC paths such as \\computername\folder or \\192.168.1.2\folder or their smb:// equivalents, if you know them already.). Officially, the change is described as disabling HomeGroups, a Windows-specific, post-XP discovery feature I still can’t differentiate from Workgroups, but for me it seemed to break discovery on the whole, including on Linux hosts.

Another change, introduced in the “Fall Creators Update”, disable support for the old SMB 1.x protocol version. This is what was resulting in the Windows share host seeming to not exist, even after the usual rain dances (yes network is connected, yes router is powercycled, yes smbd/nmbd are running, …), on freshly-updated Linux Mint 18.2 (LTS). Killing this off is at least defensible given the age of SMB 1.x and known (if somewhat theoretical unless the hackers are already in your living room) security holes, but a heads-up would have been nice.

Props to this random page for the “Suddenly can’t connect in Linux/Android”, SMB 1.x fix. In case it disappears, the fix is to open a Run dialog (Win-R) or command prompt, and type “optionalfeatures” (minus quotes). This sounds like a directive in the world’s lamest text-based adventure, but bear with me. You should get a dialog of various random features in alphabetical order. Find the one labeled “SMB 1.0/CIFS File Sharing Support”, expand it and enable the SMB 1.0 client and server.

To fix discoverability, some discovery services need to be turned back on (natch). Amazingly, the Windows 10 support article on the subject (which often appears as a link embedded in the UI near the relevant setting) is at least partially helpful. You have to scroll down to the “How do I troubleshoot sharing files and folders?” item and expand it yourself, because including a shareable anchor link to that part was a bridge too far, but the instructions within are pure gold. The instructions under ” Make sharing services start automatically” will roll back the damage caused by the 1803 update and make shared folders great discoverable again. While you’re in there, you can also follow the advice to “Turn on network discovery and file and printer sharing, and turn off password protected sharing” if you’d like. I still couldn’t connect to the share after the above incantations, but can’t be 100% sure if it was another Windows update demon, a bug on the Linux side, or just me misrecalling the username/password after years of disuse, so I enabled this (nuclear) option and finally was back to watching movies on our TV. Just be sure to check for and de-l33t any local hackers already connected to your Wifi before doing this. Check the basement, check the cupboards, and if you have a weird closet under the stairs from which crackling sounds and owl noises occasionally emanate, be sure to check there too.