Workflow Action : Copy to Sharepoint - Document Set Error

Nintex Workflow 2013.

Using the copy to SharePoint action on a document set, I'm getting the following error. I've tried upping timeouts, limits but with no luck. Document set has 300 odd files with a total size of around 280mb. Copying to itself into a renamed document set.

Error is, Failed to copy item. Cannot export a Document Set larger than 50 MB.

Any help appreciated.

Regards

Tony.