Is anyone else having an issue with putting the $300 on the 1040, line 10B. It has been working fine until today, now it will not allow the 300 to be entered on the first line, it turns pink and says value must be equal to zero. 

The 300 is carried to the second 10b line just fine and the deduction is calculated on the 1040 on line 10c, but I can't get rid of the first pink line, making e-filing impossible. An update screw up?