[exec] svn: This client is too old to work with working copy ... You need
[exec] to get a newer Subversion client, or to downgrade this working copy.
[exec] See http://subversion.tigris.org/faq.html#working-copy-format-change
[exec] for details.

Simplest fix; delete everything under this path and re-checkout.

Check your admin rights haven’t vanished (For Windows, try creating a directory in Program Files)