Unable to activate with purchase code

Hi there, I am unable to get the purchase code to activate the plugin.  It says: <div id="message" class="updated"> <p class="cr_failed_notif"> Failed to validate your purchase code with Envato. </div> <div class="notice notice-error is-dismissible"> I don't believe I am using this license with any other sites, what can you suggest?  What do you need from me to confirm? </div> Thank you!