Please see https://github.com/NodeBB/NodeBB/issues/3573
If you have a custom theme, you should switch to using cache-buster in your header.tpl
@spicewiesel I have the same problem with https on uberspace, too. Did you found a solution for this issue? Here is my thread on this 😉 https://community.nodebb.org/topic/10719/websocket-connection-problems-via-ssl-on-special-port
Just an update to those following this post, that NodeBB v1.6.0 has entered the feature freeze portion of the launch as of 31st of August 2017
Code Freeze is schedued for this Thursday (7th of September), with a launch a week later, on the 14th of September.
It's not a must, but doing it will save quite a bit of space when your forum gets large.
Link the theme into node_modules with npm link and then use grunt to watch changes and rebuild automatically.