Hi Josh,
I could now find the reason:
I noticed in your 'jdownloads_files' table the field 'publish_down' contained invalid values (0000-00-00 00:00:00 instead of NULL) !!!!
This must be the result of a faulty update from version 3.9. This cannot happen with a new installation.
However, since this value was not taken into account in the queries, the wrong results were obtained. To solve this, I have now inserted a short check in the update script. If incorrect values are found, an attempt is made to correct the field. The result of this attempt is then added to the installation log (see control panel). My first tests were successful and allways corrected the wrong values.
I have your send the new version 4.0.27 via e-mail. Please install it on your website and check the result. All your Downloads should now be listed again as expected.
I will publish the new version it by noon tomorrow at the latest.

Thanks a lot for your help to find the reason for this issue. Your backup was very helpful.
