How to fix "containing working copy admin area is missing" in SVN?

What I did to fix this was to delete the local copy of the folder under question and then do an svn update of the parent directly afterwards.

Fixed it right up.

fwiw, I had a similar situation and used svn --force delete __dir__. That solved the issue for me. Then i continued working with my working copy as normal.

According to this: http://www.devcha.com/2008/03/svn-directory-svn-containing-working.html

Check-out the folder "blabla" to a different location and then copy its .svn folder back into the original "blabla".