Sears Kenmore Refrigerator Troubleshooting Freezer working refrigerator side warm not working repair

My 10 year old Sears Kenmore refrigerator has been flawless until now. My freezer was working perfectly but the refrigerator side was warm. The narrowed it down to poor air circulation. My return vent was iced over creating a negative pressure situation preventing new cold air from entering. Once the ice was cleared the cold air started flowing again. I suspect the problem is my kid leaving the door partial open sometimes. The warm air entering creates condensation that turns into ice. Glad this was a no cost repair.