Hey David. It seems that I am also getting an Internal Server Error every time I try to create a non-Product file in Download Manager.
Steps to reproduce:
1. Visit https://developers.redhat.com/download-manager/ui/administration/products.jsf and ensure you're authenticated to your user account and have permission to create non-Product files
2. Click 'Add a new Product'
3. Enter a Product name, Eloqua product code and Thank You Page (https://developers.redhat.com/media-download-confirmation/?)
4. Click 'Save product'
You should see: