[Solved] .ini file upload, can't download the file afterwards

When I upload a file (test.ini) in a forum topic, the file is uploaded to the server (I've checked this).
But when I want to download it afterwards, I get:

Page not found
The requested page "/sites/default/files/test.ini" could not be found.

I tested it with test.xml and test.txt. Both working fine.
I added xml, txt and ini to the allowed file types (otherwise they would not been uploaded)

It seems that only the .ini file refuses to being downloaded.

Checked the database and in the file_managed table, I find the entries for all those files. Nothing different for the .ini file.

Anyone any idea?