First of all your NGINX config is incorrect. You want to access the forum under /community, but are using /forum in it.
This is a simplified version of my NGINX config:
And here my config.json:
I've never seen this error before in the admin panel:
You are running NodeBB v1.12.2.
Failed to look up latest available version of NodeBB
What might cause this?
This is happening since the code to get the version was moved to the server side, https://github.com/NodeBB/NodeBB/issues/6540