Im at Lt.Commander and i still cant get access to the mission "Skirmish". Does that have anything to do with the FE reruns mentioned on the main site calender?
This changed after the 4 November update and might be a bug. You need to reach Lt. Cmdr 2 and then you will be able to continue the missions. There are no missions available between Lt. 8 and Lt. Cmdr 2.