An empty space can remain in the spaces table if the last delete child document entry was a translation

So this one is very strange from my point of view.

Even after removing the Sandbox extension, the Sandbox space still shows up in the navigation list.

Moreover the query "select * from xwikidoc where xwikidoc.xwd_web = 'Sandbox';" doesn't return any document, so my best guess would be that this is due to a caching problem.