This is basically a warning to any one who uses CyberDuck to connect to XenForo's webdav system for the purpose of editing templates. The latest version, 4.4, introduces a pretty major issue for XenForo users: templates get deleted: This is logged in the webdav-error.log file. The file I was working on was simply "webdav_test.html". I haven't yet done any more debugging. The end result, sadly, is whatever template you are working on is completely deleted from XenForo. I'm going to tag @Mike in case he can see anything which may delete a template via XenForo's WebDAV server under certain circumstances in case that behaviour can be adjusted. Failing that I am putting it down to be entirely a CyberDuck issue and I will be raising a defect report at their site. I was reluctant to post this as a bug here on the basis that XenForo WebDav seems to work fine in other apps, and certainly seemed to work in Cyberduck 4.3. In the mean time, do not upgrade Cyberduck and stick to your original version. Personally, I'm now looking for another solution. Transmit on Mac seems pretty clunky and slow and I'd prefer a solution that also works on Windows. It seems the latest version of PHP Storm struggles to open templates from the older version now. Fun fun!