Dependents are not the same as qualifying relatives. I am going to assume this is for college entries where things can get blurry or a technical issue.
1.Students under the age of 24, full time in school, usually qualify to be dependents rather than qualifying relatives, perhaps your children are not dependents this year.
See Publication 501 - Internal Revenue Service page 11 to verify that you qualify to claim the dependent or if they are in fact, a qualifying relative.
2. Another option is that you have some piece of data stuck. Follow these steps:
Online version:
A full or corrupted cache can cause problems in TurboTax, so sometimes you need to clear your cache (that is, remove these temporary files).
For stuck information follow these steps:
Desktop version:
If this does not answer your question, please reply with more information and the area of your return.