If a dependent was initially entered then deleted, it may still appear on a worksheet in the program. To remove the worksheet, go to Tax Tools > Tools > Delete a Form and delete the "Dependent Information Worksheet"
If the error still exists, returning to the Federal section and reviewing and adjusting entries in the Deductions & Credits section may resolve the error. Be sure to expand menu options such as "See list of all income" and "Check for more tax breaks" and "See list of all tax breaks". You will be able to tell which areas you have entries, you will see a gray button "Revisit".