This article assume that you have updated zip file of plugin. And if you want updated plugin then please rise a ticket. We will provide you link to latest plugin from there you can download zip file.
This is a known issue occurring with the Visual Composer plugin.
You can update it in two ways
#1)
- Switch to any default WordPress theme(Activate any other default WordPress theme)
- Deactivate Visual Composer then delete plugins.
- Upload latest version of plugin and activate it
#2)
- You will have to delete or rename the Visual Composer plugin through FTP.
- After deleting the plugin, you can install the new plugin normally.