Tilemaps turn pink

Using Unity 2019.3.13f1 on a 2D project. Every time, after I make a tilemap and create my level then come back it turns pink, and when I play the level the colliders stop working properly. I've made the tilemap as a prefab, as a child of another prefab, and as an object in my scene. No matter where I make it, as soon as I swap scenes or click to a prefab it all goes pink and I lose what I was working on. Has anyone else run into this?