Troubleshooting : "svn: Server sent unexpected return value (405 Method Not Allowed) in response to PROPFIND request for '%DIR_NAME'"
I had this error when attempting to checkout my repository.
svn checkout https://server_location.com:8443/svn/repository_name
My mistake if not a suckerpunch was having mis-typed the location of the repository. So you may want to check you have correctly typed in the location of the repository or if the location of the repositry has been moved.
Hope this helps.