All workflows can be modified and saved.

If the submit button does not appear at the top of the workflow, there is a possibility that the workflow has either not been completed or the workflow has pre-requisite workflows which have not been approved.

To find out what the pre-requisites are for the workflows:

Navigate to Administration -> Idea Definitions.

Select the applicable Idea Definition

Select workflows on the top right

Select an applicable workflow

Navigate to the "Pre-Requisites" tab.

This will now show you all workflows that need to be approved prior to the selected workflow being allowed to be submitted for approval.