If you subscribe to my mods, then there may be a mod conflict. You start a campaign and see missions from another company. Nothing happens when I try to start. This is due to the fact that I used one template to create mods. I haven't solved this problem yet.
You must delete the file. "campaign.sqc"
C:\Users\###\Documents\Arma 3\Saved\campaign\

You will lose the saves of other campaignes