I have a feat I'm making that adds a single point of Charisma and other bonuses, but I can't seem to get the character builder to add this point of charisma. Am I just missing something?

Add Modifer >> Modifier Type: Bonus >> Modifier Subtype: Charisma Score >> Fixed Value: 1.

This will add 1 to Charisma. Note that it will not exceed 20 for the character, like other feats and racial increases. This means if your character already has 20 in Charisma, then it will not increase further. If you want the feat to be able to go past 20 add another modifier.

Add Modifier >> Modifier Type: Bonus >> Modifier Subtype: Ability Score Maximum >> Ability Score: Charisma >> Fixed Value: 1.

With this your feat will add 1 to Charisma no matter what the current Charisma score of the character is.

Quote from Cyb3rM1nd >>

Add Modifer >> Modifier Type: Bonus >> Modifier Subtype: Charisma Score >> Fixed Value: 1.

This will add 1 to Charisma. Note that it will not exceed 20 for the character, like other feats and racial increases. This means if your character already has 20 in Charisma, then it will not increase further. If you want the feat to be able to go past 20 add another modifier.

Add Modifier >> Modifier Type: Bonus >> Modifier Subtype: Ability Score Maximum >> Ability Score: Charisma >> Fixed Value: 1.

With this your feat will add 1 to Charisma no matter what the current Charisma score of the character is.