Single with two dependent children. When i check head of household an error pops up in the middle initial block for the dependent?

[Terry53029]

When you enter childrens info the error will go away 

[jbowman]

Thanks, the dependents names and ssn are entered in part 3.  If i try to enter it in part 2 another error arises saying don't enter info of dependent child shown below.  If i go from head of household to single everything clears but the tax consequences are different.   

[Just-Lisa-Now-]

whats the relationship youre choosing for the children?  and did you mark that the children lived with the taxpayer?

[Terry53029]

Do not enter in part 2 only part 3

[jbowman]

natural children.  If i mark single no problem but more taxes owing.  if i mark head of household the blocks for non dependents light up.  The children are listed in part 3

[Just-Lisa-Now-]

there is no choice for natural children, are you marking son/daughter and in the very last column of the dependent table, choosing that they lived with the taxpayer, Code L?