The one explanation for the difference would be an increase in discouraged workers. That number rose from last December by 389,000; November’s figures are not available (the historical data set was down). Also, the civilian labor force participation rate did drop to 64.3%, which indicates that people are still leaving the work force rather than rejoining it.
Ed notes that the number of jobs added barely outpaced the average number for the year. The job growth has indeed been disappointing yet again.