The advantage of KnowledgeTree is that it keeps versions of each document that you upload. Unfortunately, this does not seem to work in version 3.7.0.2, when uploading a new version of an existing file via WebDAV. The file is overwritten with the new version, but there is no version history.

There might be good reasons for that behaviour, which are explained in this issue?

Here is a solution that works for me, but of course, I do not know the interna of Knowledge Tree, therefore please use it at your own risk…
In file ktwebdav/lib/KTWebDAVServer.inc.php, find the lines:
// Modified – 25/10/07 – changed add to overwrite
// $oDocument =& KTDocumentUtil::add($oParentFolder, $name, $oUser, $aOptions);
$oDocument =& KTDocumentUtil::overwrite($oDocument, $name, $sTempFilename, $oUser, $aOptions);
It seems, with the add method a new file would be created, with a unique filename. So uploading a new version of test.txt would result in two files, test.txt would stay, and the new file would be test(1).txt. This is not really what you want.
To get real versioning, comment that line with “overwrite”, and add these lines:
$aOptions[‘newfilename’] = $name;
$oDocument =& KTDocumentUtil::checkin($oDocument, $sTempFilename, ‘WebDAV upload’, $oUser, $aOptions);
This should do the trick. You will only have one file in your folder, and when you click on “Version History” in your webinterface, you will see the old versions and the current version. The file you download via WebDAV is always the latest version. This makes sense to me…