Steps to reproduce:
1. Add the zip operation to a workflow and tag it for archive
2. Run the workflow
In the Archives tab, that element shows an unknown type. Example: http://mh-local/episode/archive/mediapackage/21f0e994-d3f9-4872-9bc7-5dae3e880103/attachment-7/0/attachment.unknown (before was fixed, the archive tab would not show anything)
Have a mime type.
Workaround (if any):