After trying to switch to a new link set, I've clobbered my header navigation, so that nothing (beyond logo, background etc) appears. I'd be happy if I could restore back to defaults, while I figure out what I did wrong.
My breadcrumbs: I deactivated the Default Link Set, and activated the edited Primary Navigation set. Synched, previewed, saw no change. Couldn't find the Component drop-down method to change the Link Set, so I edited the Header template per posts by @OliverRodrigues and others but apparently did it wrong > menus disappeared from header, all pages. Tried to restore it by undoing my edit, to what I thought was there before, so it now reads:
<div id='navbar' class='navbar-collapse collapse'>
{% assign primary_nav = weblinks.default %}
Still no menus. I notice that the posts treat the syntax as weblinks["name"]. Before I try that, I thought I'd ask: any additional clues to what to try next? thx