If you use Workflow Designer to create a new workflow, in "Diagram" mode you can select the "Create" transition and add a screen.

Screens for creating issues are actually set in the 'Screen Scheme', in the 'Create' operation, not in the workflow. This allows the user to set 2 screens for creating issues, and the one in the workflow's transition is simply ignored.

If this is performed, it blocks the screen deletion and shows an empty values (with a bullet point on it) on "Workflows" when checking all the screens:

Steps to Reproduce

• Go to workflows and choose "Add Workflow"
• In Diagram mode, click on the Create transition
• Click Edit on the right and add a screen to the transition
  • note that this is not an option in text mode

It does not seem to actually apply the screen in testing - when attempting to create an issue I am not seeing the associated transition screen.

Workaround

1. There is no workaround to remove the associated screen from designer view; you need to create a new workflow or copy an existing that does not have this screen associated.
2. If you want to set a screen to the create operation, please do so in the respected Screen Scheme. Screen Schemes can be set to specific issue types within a project in Issue Type Screen Schemes, like workflows.