Where does TGB store Sprite/Animation lists?

I'm using a repository to store my progress on the game, and so that my external developers can all share their progress. However, I'm having problems getting my externals to see new art/animations when I add them to levels. When they open up the project and the levels in question, all of the game objects are still in the level, but none of the art is attached to them nor are the Sprites/Animations even added to the project.

My externals have all of the relevant art files, and they're located in the correct places. They can manually re-add all the art and hook it up and it works just fine. But obviously we don't want to have everyone do that by hand every time new assets drop. So my question is:

Where does TGB store the information about what Sprites/Animations are loaded in to the project? Is there a file I'm forgetting to check in? Is this a bug?

Thanks in advance.