If one of our plugins fails to install, the culprit could be the active PHP version on your server. Please check the minimum PHP version requirement on the plugin’s main page, from here (search for the plugin): https://codecanyon.net/user/coderevolution/portfolio

If you find that your PHP version is older that the minimum required one, please update your PHP version to PHP 5.6 or to PHP 7.1 (or newer). We recommend that you use PHP 7.x (or newer) for the best plugin performance.

If you don’t know how to update your PHP version, please contact your hosting’s support, they will surely help you to fix this.