This simply tells that there is a version mismatch between the PHP script ('SQLyogTunnel.php') that is uploaded on the server and the SQLyog client code ('SQLyog.exe' or 'sja.exe' executables).

The tunneler script and the executables exchange data in a XML-format. Whenever we add new features (or fix bugs) we sometimes need to change the XML-schema used for this communication. In case the tunneler and the executable should 'disagree' on the interpretation of data, serious errors could occur. That is why the executable always checks for correct tunneler version before proceeding.

To resolve the issue simply upload the script that shipped with the actual version of the SQLyog installer.

You can verify the tunneler version by viewing the PHP page using a browser.