I had this problem too. If I remember correctly it is to do with the Mods you can install through JSGME. I uninstalled all the mods and then only reinstalled the ones that didn't bring up the message 'This mod is already installed by "such and such" file'. By such and such, I mean I can't remember the exact wording of the message. I carried out 2 campaign patrols without seeing a single soul before I sorted it.
Hope this is some help.
PS.
Welcome aboard, Herr Kaleun!