visual composer not working backend

No matter what theme we are using sometimes it happens that visual composer is not working in back-end mode. Sometimes it working in front-end mode 

Causes :

1) Updated Wordpress but back-dated visual composer

2) Other Composer plugin installed 

To solve this issue, first you need to check if your visual composer is latest and updated. Then check if there are other composer plugin installed, just deactive those plugins . I hope it will solve your issue