Just had an odd hiccup on the Africa map. After I completed all of the Tech advances, all of the Mercenary Camps costs turned negative, and I cannot buy any more. That leaves 350B armies that I was about to use and move on to the next map.
This bug was fixed in one of the last updates, so complete your current level and move on to the next one.
Speaking of which, I was looking forward to the US map at the end, but now it is gone. What happened?
The 2nd to last update reduced level visibility to 3 levels ahead of the last one you unlocked.
Also, this isnt the forum for such issues at all, this is the signup thread......
Try to keep up to date with
https://www.warzone.com/blog/ , Fizzer posts all of the updates there.