Slitherine

Hi,
I am having some problem playing the Coral sea scenario on the Japan Campaign.
My aircraft resources are *20*, but when I try to place an aircraft that is not a
floatplane (like zero) the deploy hexes turn red and its says that "there is not
enough air supply available to deploy the currently selected unit here. Any ideas
what can be the cause of this problem, or bug?

Try to deploy an aircraft carrier. As opposed to floatplanes, your other aircraft need a place to refuel and refit.

Thanks Cortilein, that really helped. I think it should be explained in the game
cause its not that obveios. But there are 8 points left and no more then 4
aircrafts are allowed before I am getting those red hexes again.

Carriers only store a certain number of air units (max. 3 for a fleet carrier, less for CVL/CVE). It might be that you need more than one carrier to deploy further air units.

Thanks. But what is CVL/CVE?

CVL - light carrier
CVE - escort carrier

Those are smaller then the big fleet carriers, so carry less airplanes.