http://unseign.com/tag/hat/ go to this site This is bit odd behavior but you will notice that sometimes in your Office 365 site collection you do not have option to add SharePoint 2010 approval workflow. You will see all the other workflows i.e. SharePoint 2010 Disposition, SharePoint 2010 Collect Signature etc but you do not have option to pick Approval workflow.
I tried researching on this issue and only workaround that I have found so far is that deactivate the “Workflows” site collection feature and reactivate it again.
The challenge with this approach is that many times you are already using other workflows which comes as a part of “Workflows” and many instances are already in flight and the million dollar question is what happens to those workflows when you pull the trigger and de-activate the workflow.
Honestly I do not have the official answer for this but I have faced this issues and my recommendations are as follows.
1) Make sure your all your workflows are set to no new instances.
2) If possible complete all your inflight workflows.
3) Where possible take the backup.
After performing above steps you can go ahead and de-activate the “Workflow” feature and re-activate it again and your “SharePoint 2010 Approval” workflow should show up.
Just to verify the behavior I de-activate the feature with existing inflight workflows and re-activate the feature and all my in flight workflows were running just fine.
Having said that I would follow the above recommendation in Production.