Recently I had come up with an issue regarding permission of workflow and workflow got cancelled.
"Access denied. You do not have permission to perform this action or access this resource." SharePoint 2013 workflow cancelled.
By default, workflow does not have permissions to access the app request catalog. Catalog lists in SharePoint require owner (full control) permissions. Workflows generally run at permission level equivalent to write.
To solve this, workflow should get elevated permissions. If you have properly configured the SharePoint 2013 Workflow platform and workflow is created through designer just activate the below feature from site settings.
Activate site feature "Workflows can use app permissions"
Site actions > Site Settings > Site features > Workflows can use app permissions
Workflow started working as usual.
Hope this helps....
