.....and you have entered the correct License# and email addy for the "renew"http://www.wsftple.com/renew/ .... then followed your recieved email instructions to the letter....clicked the "renew now" link and get the following on the page....
WS_FTP LE Renewal Activation
License has been successfully renewed
I just did this and all works fine for me ...
OR .... Go to Start > All Programs > Ipswitch WS_FTP > Manage WS_FTP License