Deprecation of the Workflow in Workflow Manager

When Working with Share Point Workflows (Workflow Manager) you might notice following error in the event log.

The associated workflow has been deprecated.

In the normal system state this error should never happen. However the Workflow Manager Client API allows you to write peace of code which does not have to always
be aligned to expected system behavior. IN other words you can damage lot of things if you are not careful.

For example, following command would simply delete all workflows from the system:

client.Workflows.Delete();

The next one would delete specific workflow:

client.Workflows.Delete(“Workflow Name”);

Another way to delete the workflow is to remove manually scope from database.
This article describes why should you do this: http://developers.de/blogs/damir_dobric/archive/2013/04/11/sharepoint-workflows-cannot-be-stopped-in-workflow-manager.aspx

The error above is not dangerous for the system. It is only dangerous for the “associated workflow”. It basically means that Service Bus has pending messages in the Workflow Subscription (this is how Workflow Manage dispatch messages internally), but there is no workflow (it is deleted) which should consume them.In this case this is good, because keeping of messages in subscription queues would continually increase amount of data in database if no subscribe receives them.