"No existing sandbox found. Preparing sandbox to start on game activity."

I want to use API but suddenly this text("No existing sandbox found. Preparing sandbox to start on game activity.") is repeated. Every API scripts don't work since the text. +Your scripts are currently disabled due to an error that was detected. Please make appropriate changes to your script's code and click the "Save Script" button. We will then attempt to start running the scripts again. If this script was installed from the Script Library, you might find help in the Community API Forum. For reference, the error message generated was:  Error downloading scripts (probably no scripts exist for campaign.)

The API sandbox won't start running until there is a player (any player, including the GM) actively in the game. The other message is what you see when you have no scripts loaded into the game.

You also have to have at least one script installed or you get this message as well.