if you have your GUI Listen Address set to http://0.0.0.0:8080/, then when you click "Open Webinterface" on Syncthingtray, it opens a browser and actually tries to open the address http://0.0.0.0:8080/, which does not work. It should open the browser at http://127.0.0.1:8080/.
if you have your GUI Listen Address set to http://0.0.0.0:8080/, then when you click "Open Webinterface" on Syncthingtray, it opens a browser and actually tries to open the address http://0.0.0.0:8080/, which does not work. It should open the browser at http://127.0.0.1:8080/.