Selective Service: As a rule (with a few exceptions) if you're a male between the ages of 18 and 26 you need to register with Selective Service.
Child Support: A common problem is when applicants can't prove that they are supporting their children. Proof usually requires court records, canceled checks, bank records, and affidavits from the custodial parent.
Criminal Records: This is the most dangerous problem of all. Why? Because if you file for citizenship after committing certain crimes, not only can they deny your application but Homeland Security may also take you into custody and place you in removal proceedings. If you have ever been arrested we urge you to not even think about filing for citizenship unless you are represented by an attorney.
Unable to Read, Write or Speak Basic English: If you're over the age of 50 and have lived in the United States as a lawful permanent resident for at least 20 years or if you're over the age of 55 and have lived in the United States as a lawful permanent resident for 15 years USCIS can waive the language rule. Additionally, even if you do not qualify under these exceptions, you can also in certain circumstances get a medical certificate that allows you to avoid the language requirement.