I get an message that says Invalid Text Box

If you see this message in a text box when you view it, it means that you are using a text box number which does not exist in your RPG file. It happens most commonly when you delete textboxes which are still referred to from somewhere, or if you pass a bad argument to show text box.

You might get this if you are working on several games sharing a script that you needed in both games.

E.g: in the script you first game you are using text box 544. And in your second game you have created only 471 text boxes. So when the script run it searches for text box 544 and obviously can't find it.

To solve this problem, use search text function to get the number of the text box you need and replace it in your script.

Note that if you had created text box 544 it would have shown it but the text box may have not the text you wanted to show in it. Don't forget text box conditionals like running scripts. The lesson is to always playtest throughly :)