I downloaded the Visual Composer 4.7.4 and uploaded it to my site via ftp. I can see the plugin in my dashboard plugin area. When I try to activate the plugin, I get this error:
Plugin could not be activated because it triggered a fatal error.
Fatal error: Cannot redeclare wpb_getImageBySize() (previously
in /home/riiott/public_html/wp-content/plugins/js_composer/include/helpers/helpers.php on line 110