This can happen if you are using GD Rating System Pro additional addons (like Multi Ratings or User Reviews addon). If that happens, make sure to disable GD Rating System Pro and all addons for it, and upgrade main plugin and all its addons, and reactivate them after the upgrade is done.
All Dev4Press plugins and addons require jQuery. But, they will work only if the jQuery is loaded with the WordPress proper Enqueue method. If you are replacing jQuery that comes with WordPress with some other version loaded from other location, my plugins will not function properly, and that goes the same for most of the other WordPress plugins that depend on the proper way for loading jQuery.
When you install User Reviews addon for the first time, it may happen that new templates are not properly picked by GD Rating System Pro. To remedy that, simply open GD Rating System -> Tools -> Recheck and Update panel. You will see the update messages, and that will reload all available templates, and reviews should be OK now.