I have document! x 4, and with a serial number, you said "If you hold a current Document! X Subscription license, or purchased Document! X 4 on or after 20th February 2006, you can upgrade to v5 free of charge by clicking here." But I tried, It said "The URL used to reach this page was invalid", Could anybody tell me why is it happen, and How I could solute it. Thanks, everyone!

I believe we have answered your query this morning via support correspondence. We look forward to helping you resolve this issue.