What do you mean? Could you describe the problem in more details? Do you experience compatibility issues with Visual Composer 4.9 only? Or you just can’t use the plugin?
Please understand that this plugin works only with compatible themes. Do you use a compatible theme?
This plugin is not suitable for normal WordPress user. It was created for WordPress themes developers, which is clearly stated at the plugin’s description page in “Before you rate/review the plugin” section.
I’m not able to replicate the issues you experience. I’ve tried the WebMan Amplifier with Mustang theme and the most recent version of Visual Composer (which is now 4.10) and everything works the way it should for me.