This error means that the user's Site Role doesn't allow them to Bypass workflow, but there isn't an applicable workflow available for the type of action they're taking.
If your site uses workflow:
Edit the appropriate Workflow Definition and ensure the user's Group is included in the Groups field. Only Groups selected there will be permitted to submit assets using that workflow.
Ensure there's an appropriate workflow type for the action the user is taking. For example, to delete a page, there must be a Workflow Definition with the type "Delete" applied to or inherited by the asset's parent folder.
If the user should be able to skip workflow altogether, edit their appropriate Site Role to enable the Bypass workflow ability.
If your site doesn't use workflow:
If your site doesn't utilize workflow at all, you can disable workflow requirements entirely by following these steps:
Right-click the base folder of the site and select Workflows.
Under "Require workflow for all contained assets" select "No".
Check "Apply setting to contained folders" to propagate the change to all subfolders.
For more information on creating and applying workflow, please see the Workflows article in the Cascade CMS knowledge base.