Webdrive (http://www.webdrive.com/) is a WebDAV client for Microsoft Windows. When it is used to move files to or from an Alfresco repository the following error occurs in alfresco.log:
ERROR [org.alfresco.webdav.protocol] WebDAV method not implemented - PROPPATCH
This does not appear to affect functionality.
PROPPATCH is a standard WebDAV method described in RFC4915 (http://www.webdav.org/specs/rfc4918.html) where it is stated that "All DAV-compliant resources must support the PROPPATCH method".