Related to Incentive theme

We have used the incentive theme for our website. But the Incentive theme purchased by our previous developer. But now we have no contact with that developer. So, there is no option to get the new version of the theme. We have updated the wordpress version to latest. So, the visual composer plugin is not working now. We have purchased the Visual composer plugin from your account. While activating the VC, we could not able to activate that. We could see that the “HTTP ERROR 500”. We have contacted with the plugin support team and they said that there is the ttheme developers changed the VC code. Please let us know your comments ASAP.