Imported Workflow Blank In Nintex Workflow Designer
When the "Import Workflow" functionality of the Nintex Workflow designer is used, the import appears to complete without error, but the workflow actions aren't imported. Other information, such as workflow variables and workflow settings are properly imported.
Activate the Site Collection feature:
Go to: Site Settings > Site Collection Administration > Site Collection Features
Look for the “Nintex Forms for Nintex Workflow” feature.
If the feature is already active, de-activate and re-activate the feature.
This will occur if a Nintex Form has been embedded in the original Workflow as part of a task action, but the destination site is missing the “Nintex Forms for Nintex Workflow” site collection features.