I am doing iowa state tax return and on the capital gains worksheet it says I have too many characters in the Payor 1 entry. How do I change that?

The error is on the dividend work sheet which isn't even filed. The Payor 1 is American Funds Service Company and I guess I need to change to American Funds Service Co.  It won't let me file until I change and I cannot change it.  It lets me highlight but not change.