Membership 2 Pro - Warning when a membership is cancelled

When I cancel a membership, I get the following messages:

Notice: Undefined variable: subscription in .../wp-content/plugins/membership/app/model/class-ms-model-communication.php on line 1019

Notice: Trying to get property of non-object in .../wp-content/plugins/membership/app/model/class-ms-model-communication.php on line 1019

Warning: Cannot modify header information - headers already sent by (output started at .../wp-content/plugins/membership/app/model/class-ms-model-communication.php:1019) in .../wp-includes/pluggable.php on line 1216

After troubleshooting I found out that my plugin WPBakery Page Builder (a.k.a. Visual Composer) is conflicting with your Membership 2 Pro plugin.

I heavily rely on WPBakery Page Builder, so I cannot keep it disabled. Please help.