Disconnected (Inactive) - no route to host

After successfully having Syncthing running for a while, suddenly I get this message: Disconnected (Inactive). In red under the “address” section of the “remote devices” when logged into the web GUI for my Mac it says “no route to host”.

I have tried restarting the mac, the NAS and my router. I am running this on a NAS with TrueNAS OS.

Can anyone help to solve this issue?

Please bear in mind that my knowledge of “ports” and “consoles” etc is extremely limited, so please include all basic steps in any advice given!

Many thanks.

I forgot to add..

The max firewall is allowing Syncthing. The mac firewall setting do not seem to allow me to allow a specific port.

I had a dig around in my router settings but I don’t really know what to check or change there with regards to port forwarding. In any case, I don’t think anything has changed which would suddenly result in it not working.

Any help would be much appreciated.

Since the setup was running for a while before the error popped up, is the Docker container with Syncthing on the TrueNAS server actually running?

Thanks for the reply. The app was running on truenas.

After a lot of research and asking Ai last night, I found the reason. Something changed with a version of MacOS (I assume) that meant that Syncthing was denied local network access in the privacy settings in Mac OS. I allowed this and it fired up as normal.

Hope that helps someone else out in the same situation.