svn: The path '.' appears to be part of a Subversion 1.7 or greater
working copy. Please upgrade your Subversion client to use this
working copy.
I am currently having this problem. I can not do anything from command line but was able to do svn work using Eclipse Subversive.
I can't/don't want to install Subversion 1.7 or greater. Given this circumstances, what can I do to fix this problem? Are there any workarounds?
I think you could do a fresh checkout of the repository with with svn co ... from command line and continue working with the command line client. Of course, it might be that Subversive won't work with that repository or will suggest to do an upgrade to the new working copy format.
As soon as you checkout or upgrade your working copy with Subversive, you won't be able to use the command line client.