Error message: "There are not enough licenses"

I have been using Timeslips since 2008; my current version is Timeslips 2011.  I have only ONE computer for my business; hence, I only need ONE license to use Timeslips.  Yesterday for the first time I received the following message:


"There are not enough licenses to allow use of the program at this time.  Please refer to your Sage 2011 License Agreement for more information."

I already have the only license I need, so I have no idea why I am getting this message.  This problem is preventing me from even getting into Timeslips to do work.  Please help.  Thank you.