Issue
When a new workflow is created, this may show a blank page like the image below:
Cause
This is usually caused by the [wf_workflow_version] Submit UI action and the [global] Submit UI action being customized.
Resolution
1 - Go to UI actions > Filter Name = Submit, Table = wf_workflow_version OR Table = Global
2 - Once you open the wf_workflow_version Submit UI action, you will see that it is referring to the Global Submit UI action.
3 - Verify that both [Global] and [wf_workflow_version] Submit UI actions are active.
4 - If the above two UI actions are customised, try to revert to out-of-box (OOB) and see if it works.
