You probably have another plugin that is using the hook filter:parse.post that is not passing the correct data back, check your plugins for the ones that are using that hook.
Can't get into plugins on admin settings
If I go to account settings and then plugins, it won't load (hangs there).
This is what I've found on the console (hope it helps):
I'm using NodeBB v0.6.1 (branch: 0.6.x, commit: 7682b56)
Those errors usually mean websockets are not proxied correctly, make sure your nginx setup is correct. If you are using cloudflare you need to disable acceleration. They don't support websockets on smaller plans.