The File Gallery Template option has never worked since I have been using Tiki from Version 12 on.
I wish it did, I wish it worked and I wish we would consider finishing the feature or at least consider it as something to go on the wish list (I can do that myself).
There has been some discussion recently about the File Gallery Content Template option at https://tiki.org/forumthread59498?topics_offset=4 and it appears no one really knows what it was for, or who developed it.
I have a very strong opinion on what it was intended to be. It was intended to be a way to assign a set of headings or prompts in the "File Description" area of a particular file. Because there is something missing in the philosophy of the File Gallery, and the file descriptions, there really is not an intuitive way to add items like "Copyright" "Author" "Artistic Medium" "Location" "Museum" and on and on and on. Sure we could add it manually, but then you'd have varying appearances as you have multiple users with their own idea on the format. There would be no consistency.
If you go to this page at https://commons.wikimedia.org/wiki/File:Stiftskirche_Herzogenburg_Deckenfresko_Pfingstwunder_01.JPG
and scroll down to the information template you'll see "Description" "Date" "Source" "Author" "Location" and then further down you'll see (my personal favorite) the "License". The License is the most important of all.
I know we can do a tracker for this, but honestly, my brain is having an incredibly hard time getting wrapped around the tracker theory.
If we had a way to create a content template for the File Description area, then we could have a pre-populated set of parameters for the file contributor to fill out.
If I only had one wish, it would be to at least have a way to populate the very important information of licensing. Public Domain, CC Share Alike, etc etc.
I really believe that whoever created the File Gallery Content Template option had a wonderful idea, and that is where it was supposed to benefit, in the File Description field.
Thanks for reading!