Factorio Forums

Todays FFF explained how to add a thumbnail to a mod file so of course I've immediately updated all my mods and removed thumbnails from galleries on the mod portal.
While thumbnails are still showed correctly, one of my galleries is now invisible to players.

I suspect that the mod portal assumes that the first image in the gallery is a thumbnail (incorrect assumption) so it doesn't have to be shown in the information tab on the mod page.
However, it isn't showed as a thumbnail either because the thumbnail is provided with the zipped mod. (And the picture from the gallery would be to big for a thumbnail anyway.)

Here's the link to my mod page. It should have a big picture which shows how it looks in game.

This is intended legacy behavior for 0.16 mods. As soon as you upload a 0.17 version of your mod, the gallery will start showing up even if you have a single picture in it.

Couldn't you make a rule that the legacy behavior is used only when an image from the gallery is used as thumbnail.
You already have ways to check it so it should be a matter of adding one condition.