I just recfeived direct support for my problem.
Thank you so much for your assistance. I deleted the EncryptStick Settings folder, then ran the program, entered my license key and reloaded my existing vaults. All is good again!! 
I really like this product and would not want to be without it – so receiving such prompt and appropriate support and being able to correct whatever issue caused the problem – makes me value SanDisk for my electronic storage even more.
Thank you, thank you, thank you.
Mike
