Note: This is just a general guide about problems that might occur during plugin activation.
On occasion, the plugin has problems getting activated in the first place, or producing errors after the license key has been entered and confirmed. Without a confirmed license, the plugin is only loading essential files, therefore requiring less server memory (but still more than your site would utilize without the plugin). Once a license has been confirmed, the plugin will activate all features, therefore requiring more server memory. And the more complex your site’s theme is in terms of provided features, particularly custom post types, and the more other plugins have been activated, the more likely you are to exhaust your memory. In theory, WordPress can handle an unlimited amount of plugins and data, but it needs the resources to do so.
So depending on your current memory setup, your site might not have sufficient memory available to support the plugin and all its features. In those cases, the plugin will fail and often times produce a white screen. If that happens, you should access your site via FTP server and rename the directory the plugin is located in, which will effectively deactivate the plugin, giving you access to the admin section again.
After that, you should check your current server memory setup. A good free plugin to check your current memory setup can be found here:
http://wordpress.org/plugins/tpc-memory-usage/
Information about how to possibly increase the server memory can be found here:
http://composer.tekanewascripts.info/manual#Memory
Before trying to re-activate the plugin again, you should add the following lines to your themes “functions.php” file:
update_option('ts_vcsc_extend_settings_customTeam', 0);
update_option('ts_vcsc_extend_settings_customTestimonial', 0);
update_option('ts_vcsc_extend_settings_customSkillset', 0);These lines will disable the custom post types associated with Visual Composer Extensions, which is sometimes just enough to get the plugin working. Of course, that means that you won’t be able to use the custom post types and all their associated elements, until you manage to increase your server memory.