You will need to upgrade SI5.2 first (recommended). If you click on START > ALL PROGRAMS > D-TOOLS > Check for Server Updates it will run the SI5.2 update first. Then you need to check for updates again and it will then run SI5.5.
Run Check for Server Updates 1st. (updates the LANSync server)
Run Check for Updates 2nd (updates the client)
Read this before upgrading -
http://www.d-toolsblog.com/product-v...update-notice/