you mean visual composer as wordpress plugin ?
Ask support, on my site I think it just worked by default.
Have you tried disabling all other plugins?
Yes if one of your plugins is not working properly, to pin point the problem you should disable all other plugins. If the problem disappears that means one of the other plugins was the problem. So you enable them one by one to see which one is causing it.
Also it could be the theme you're using especially if you downloaded it for free instead of purchasing it.
Yes if one of your plugins is not working properly, to pin point the problem you should disable all other plugins. If the problem disappears that means one of the other plugins was the problem. So you enable them one by one to see which one is causing it.
Also it could be the theme you're using especially if you downloaded it for free instead of purchasing it.
Seems like it's probably an error with the w3 total cache plugin you have installed. If the problem is still persisting after you disabled all of your plugins, it could be your theme, try switching over to default wordpress theme and see if that fixes the problem.
And sometimes errors still show even after deactivating plugins and it's necessary to completely uninstall them to get rid of the problem