Disabling or moving node/add/[content-type] links from beneath "Add content" in the navigation menu also removes them from the Add content page (node/add)
Short story: Turn the navigation menu off on any site for which you are customizing the user experience, it is only going to cause you pain.
Seeing "You have not created any content types yet. Go to the content type creation page to add a new content type." when you know darn well you have content? And node/add/page, say, still works?
Is it a bug, a feature, or 'gee. huh' that moving a content add form out from under "Add content" in the navigation menu will also remove it from the node/add page?
i mean, move node/add/story from its place in the navigation menu and it disappears from the node/add page?
in Drupal 7. Finding no documentation. It's not too bad since you can't delete the "Add content" link. I'm going to go with calling it a hidden feature
Steps to reproduce:
go to any drupal 7 site, /admin/structure/menu/manage/navigation -- move both Article and Basic page (on a default install) out from under "Add content"
now visit node/add -- and it will tell you that you have no content types
now, just disable the node/add menu link that is parent to node/add/article etc, and then the page still works, which is good
IRC response: omfg why would you do that o_O :D
why should you try to change the menu structure
A: if someone wanted to group their content in the menu
ow I see
"Add serious content" - page, article. "Add silly content" - poll ;-)
i imagine it's a "you're weird if you do that, deal with it" issue at D7 at this point, because i don't think we'll be changing how system_admin_menu_block() works
Note: This was actually caused for me by a Drupal 7 dev/alpha upgrade through beta to release candidate, which left the Add content menu item stranded in the Manage menu rather than going with its Basic page, Article, etc. children to the revived Navigation menu.