Last I read there are still two important tasks the A400 cannot do with no solution in sight.
Air refueling of helicopters due to wake issues.
Simultaneous paratroop drops out the side doors without them being swept together and hitting each other in the airstream behind the aircraft.
C-17 had both those issues. The wake problem for helos had a solution but since no one ever bought a C-17 tanker version, that was mooted. The troop drop issue was driven by the width of the C-17 and was thoroughly resolved. The A400 is less wide than the C-17 so it should have a less severe problem in that area than C-17 so the C-17 solution should work for A400. On the other hand the turbo props result in a very different flow field behind the aircraft than C-17 and if that is the primary driver, then a very different solution would be needed, assuming there is one. Maybe run the outboard engines to max power while running the inboards at a much lower power setting during the drop?
How many countries are doing operational helicopters refueling and paratrooper air drop?
Does it matter how many? If the primary customers (UK, France, and Germany) have those requirements and the aircraft cannot meet them, then what is the point of the program? Other than being a jobs program of course.