Adding assets to Xcode problem

I've an Xcode project which has been using svn, but we had to stop using it. Since then when ever I try and Add files to the project I get the error window below. The files actually get added to the file system (using Finder), but not to the project,so not disp开发者_Python百科layed in the file system in XCode and therefore can't be accessed.

I found the answer myself.

Just make sure you delete all the hidden .svn files / folders