Jelle,
Having some problems with the Downloads and I'm on 6.0.5. Basically a members secondary usergroup allows them to download products but when they are logged in and click on the latest downloads in the blocks or the downloads.php, they get:
Then it redirects them to downloads.php where they see no files at all. I've checked the permissions and everything looks good. One of our members has two different secondary groups that allow them access to the same download categories, not sure if there is a conflict there.
It is working because as administrator I can see the downloads and it does not tell me Invalid File ID. Thanks for your assistance.