Hello,

Navigate to Revolution slider and add a new slider if you get any messages, please make the screen and provide.http://prntscr.com/kworo9 Also provide your site admin access if you have any messages

If you are trying to upload a template or use addons Revolution slider will require a license. As for the common slider, it is free and available. You can edit one of the existing sliders it would be easier.

Best Regards