TT Screen is black?

I'm completely new to Roll20 so it  may be user error but my players can't see the table top at all.  it just shows up as a black square.

Hello Flynn R., First things first. Welcome to Roll20! I have moved this post to the Specific Use Question & Macros forum. This will be the area to post in if you want to know how to do something with Roll20. With that, it sounds like you have the Fog of War enabled. You will need to Reveal areas that you want your players to see. Additionally, you can test what your players are seeing by selecting Re-Join as Player button . Let us know if you have any further questions or issues.