Airborne drops not allowed

[Belphegor]

I recall that in WitE you couldn't drop airborne on a hex with an enemy combat unit, whether you could see it or not.

Appears to be the same in WitW. However, while I couldn't drop on the turn of the invasion I could drop the next turn (right on top of a unit)... so I'm not sure I understand why I could do it D+1 and not D+0

What I read is that they should have been allowed to drop on D+0 and fight for the ground.

edit: did have lots of transport. Unit from same base chosen 2nd successfully dropped on empty hex.
As well, I got the same message I got when trying a disallowed airdrop in WitE

[RedLancer]

That's odd - you can drop on enemy units. Which scenario? Is D+0/D+1 Turn 1/Turn 2?

[Belphegor]

Was a campaign game 43-45. Server game vs. Pelton.

Unfortunately it's turns past.
D+0 was turn of the invasion.
D+1 was turn after invasion.

So everybody amphib landed. But no airborne that would have to fight landed.
Then next turn they could... but by then they landed on insurmountable odds (I dropped them as an experiment to see if I could)

[Baelfiin]

Would be interesting to test if a drop hex contains three units when you try to drop if it gives you the error message

[RedLancer]

Also the rules change - on D+0 you must be adjacent to an invasion hex. A turn later within 8 hexes.

[Belphegor]

hmmm. I think I was adjacent but I can't say with certainty.

I'm guessing I wasn't. I'll have to watch for it next time. Let's assume for now I wasn't.