Hi User,
Autoback of data will be taken before upgrade. The backup (.data file) will be available in <sdp_home>/backup directory. You can download the corresponding build at : http://archives.manageengine.com/service-desk/ and install (may be in a different machine). Restore the data (the latest backup) using the <sdp_home>/bin/restoreData.bat file. Please provide us the support ticket id raised for this issue (so as to follow that up).
regards,
Uma..
SDP team..