I cant get the tiles to appear in the tile pallete

I am trying to make a top-down RPG game in Unity 2D. when I add my Tileset into the Tile palette the tiles won’t appear. I can still use the Tile Palette to draw the tiles but the palette is still a grey grid. If anyone can tell me how to fix it it would be greatly appreciated, thanks!

Sorry, I forgot to mention I’m on Mac and I’m using unity 2018.1.0f2 personal 64 bit.

This is apparently a known issue and fixed in the beta branch.