I am still using Voxel Version: 1.6.1.2.

When I try to run an OttoKit work flow I get the error below:

There was an error(s) with your Workflow.
Action execution failed: PHP Error: Call to undefined method Voxel\Membership\Type_Default::to_array()

But the workflow is not to pull the Membership but rather the user ID or “Post Author”

Not sure if this is a direct result of not being on the latest version of Voxel.