American Campaign Mission 2 over, but mission 3 does not start.

Hi everyone.
I just started playing this game a couple of days ago and I completed the first two missions in the American Campaign but after completing the second mission, my game now says I have to start from Mission 1 again. The 'continue game' button shows American Campaign, Panama Canal as the next one but when I click on it, the game just shows me the first mission. The second mission is not available to choose either, except from my save games. I tried playing the save game of second mission again and won but the game still does not allow me to go on to the third mission. I had closed the game and the PC after winning the second game, but I dont know why it should have affected the game this way. Could someone kindly help me go on to the mission 3 and the rest of the missions without having to play mission 1 again please?

Sir, I use Windows 8.1 OS, with 8 GB RAM, and the game is the Steam version. Maybe there is a configuration file in the game that I can edit to make the game recognize that the first two American missions have been completed? By the way it also seems that the steam achievements are not being activated.

Issue solved, I just used a save game I had of mission 1 and quickly completed the mission and now mission 2 and 3 are available.