Membership Pro - Warning messages at cancelation when Member Player plugin is active

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 the first test, I thought this was related to Visual Composer, but then I continued testing and I realized that this is happening when Member Player plugin is active.