Is there a limit to the number of Formulas that can be included on a Form?

 

I have a form that has 13 formulas, and I have tried to add another one, but no matter what formula I put in there (I have even tried to copy other formulas already on the Form that are working) it keeps disappearing.

 

I will put in the formula, and click "Done" and it will save and appear in the screen. But when I go to View to try to add it to the View, it has disappeared, and when I go back to the Form, it is no longer there either.

 

Why does it keep disappearing?

 

Thanks, Roger