The Subversion manual states:
\'!\' Item is missing (e.g. you moved or deleted it without using svn). This also indicates that a directory is incomple
\'!\'
Item is missing (e.g. you moved or deleted it without using svn). This also indicates that a directory is incomple
What exactly did you do to the branch before you received this error?
If you're having regular problems with SVN, you're probably doing something wrong (e.g. using mv/rm as opposed to svn mv/svn rm on the branch).
mv
rm
svn mv
svn rm