Thanks for this.
I think you have given it to me before.
I am changing between computers a the moment so I sometimes miss things.
the person who originally posted the 'missing flak' only spoke of missions in the pacific, and sounded like they were using my ships.
I now know that I have built ships with a dp on larger AA guns that will not show flak explosions in the game (as posted).
At the moment (without my computer), I do not know which ships have this (and there are probably a fair few)
I think they are just missing the immersion with the flak explosions, and that was my fault with the dp.