Is Syncthing actually running on that machine? There was some incompatibility in the Go programming language (which Syncthing is written in) not supporting older Mac OS releases anymore. Maybe that’s why the program doesn’t even start at all?
To be clear, you’re trying to reach the GUI of Syncthing’s on your “remote” machine, but from a browser open on that machine itself, right? Accessing it from other computers remotely won’t work with the 127.0.0.1 address.
Yes sorry Syncthing is running on the remote machine. I’m logged into that machine via Jump Desktop and can verify it is running. Thats how I’m going about trying to get it all set up, via Jump Desktop.
I use the “Open” menu option form the menu bar of Syncthing. Here is a screenshot over Jump Desktop of the remote machine.
The output above means that Syncthing either isn’t listening on port 8384 or it’s not actually running (odds are it’s the latter).
In the second screenshot you posted on Dropbox, the Syncthing tray icon status indicator appears to be gray and flagging an error (are you using the Syncthing for macOS bundle?).
Syncthing 1.23.4 requires Go 1.19 or higher, but Go 1.17 on macOS requires at least 10.13 (High Sierra). So although the tray icon in Syncthing for macOS can work because it’s a native macOS application, the Syncthing 1.23.4 binary bundled with it unfortunately won’t (Syncthing’s log file will provide more detailed info).
I was using the dmg in the link you provided already, but DL’d it and installed again with the same results. By “Tray icon” you mean the pull-down in the main menu bar? If so then yes that’s working but maybe Syncthing itself isn’t actually running?
The OS on that Mac as mentioned is 10.12.6 and pretty sure it can’t be updated further. Does that mean I’m SOL with Syncthing?
Yes, the pull-down/drop-down menu in the macOS menu bar.
(Most operating systems with a graphical interface have a main “menu bar” / “taskbar” / “toolbar” with an area that’s reserved for a clock, status indicators – e.g., Wi-Fi – and special shortcut icons. That reserved area is often referred to as the “tray”, or per Microsoft Windows lingo, the “system tray”.)
Syncthing for macOS comes with a tray icon that’s basically a launcher and status indicator for Syncthing – i.e., the tray icon and Syncthing are two separate apps. Think of it like a remote control for a TV. The remote is working, but not the TV.
Currently, OS X 10.13 or higher is necessary. syncthing-macos is packaged as a disk image as an application bundled with the syncthing binary.
If you want to continue using the tray icon app, you’ll have to disable its auto-upgrade feature so that you can stick with a manually installed older version of Syncthing. (There are a number of posts on this forum regarding downgrading to older releases of Syncthing.)