Culverins refusing to obey orders

[Sweger]

I am currently defending in a siege for a fortification in the Britannica campaign. The Welsh are trying to break through the walls with a unit of catapults. Then I moved out three culverins and chose explosve shot, so I could pound the Welsh while they're using their catapults. My culverins are at the front of the gate but refuse to shoot. I spread them out, but it won't work, activating "firing-without-orders-mode" won't help either. And the Welsh are in range and I guess not too near either, since the arrow-bow-cursor is green, without any blinking or such. When I order them to fire (individually) they shout "attack" move slightly and then say "Orders carried out my king!", and then nothing happens, no matter what I do?

Os there anything I can do about this?

EDIT: The fortification as on a hill, and the Welsh were standing "on the way up" so to speak, if you get what I mean. Could that be it that artillery on a hill cannot fire upon units advancing uphill on the same hill?

[Silverheart]

Well, if the enemy is standing on the incline of the hill, it only makes sense that your cannons can´t fire on them - they would just hit the hill.
However, they should logically still try to...
But yeah, you should try to place them where they have a clear view and the enemy directly in front of them - cannon crews can get a little cranky about these things.

[Avatar]

If I understand correctly, you are trying to fire downhill with artillery. That wont work if the enemy is too close because the arc of fire from the cannon barrels would just go right over the heads of the target.

Other than mortars, if you are playing one of the few factions that gets them, artillery is mostly useless on siege defence. Actually it is good for one thing, park the siege engine in front of a breach and it messes up the enemy charge formations when they try to get past.