difficult to say without detailed informations...
1. check your media folder
for the download_gallery (default folder is media/download_gallery), was the upload correct?
2. uploaded files are maybe inactive in the mask to add this item or (after upload) in the list
3. do you have this file in the overview and, if yes, is active (and green) or maybe like my screenshot, inactive and red
4. have the file one of the allowed file types?
5. is it possible to read the error log, maybe you have there more infos about possible errors
6. it's possible, that the upload works, but not the entry of this item, into the database - try again to upload a new file, check for media-folder for this - if the upload works and you dont have in the overview, its a script- or database-problem. check the database for this file - table: mod_download_galler
y_filesAdmin Edit.: two threads for the same theme? i delete the other one