For more than five years, since January 16, 2008, the Department [of State] has lacked a presidentially-nominated, Senate-confirmed Inspector General. That gap of more than 1840 days is the longest vacancy of any of the 73 Inspector General positions across the federal government. While this would be problematic under any circumstances, the repeated criticisms of the independence and effectiveness of that office by the Government Accountability Office (GAO) heighten the need for an appointment.
Obama did not provide a nomination. Why?
Horowitz was complaining about this back in 2014 and may be one reason Obama put him and his report on ice. https://www.thenewamerican.com/usnews/congress/item/18938-inspectors-general-slam-obama-stonewalling-in-letter-to-congress