Clearing Data from Data Management Step

To perform such Data Mgmt tasks such as clearing data, then the affected entities must be associated with a workflow profile, and there must be an Import workflow that is active.
That is what the error message is telling you.

I suspect you have data loaded through a central workflow profile (not recommended if large data volumes, for performance reasons), and either you don't have local entity workflows, or not all the entities are assigned to a workflow profile that has an active Import workflow in it.

If you really don't need to import data through the local entity workflows, then you should enable the Import workflow on each entity's workflow profile, and set the type to Central Import.  That tells the entity workflows that the data is being loaded centrally, and doesn't perform any workflow tracking at local entity level. As soon as that is enabled, the error should go away.