Original Post — Direct link

So "AI ships getting stuck at shores":
-caused by AI ships trying to get to civilian buildings deep in land, these buildings are set as HarbourBuilding, meaning the AI thinks its a harbor building and tries to get to it to attack it, but its not, its deep in land, so AI will try endlessly but never reach it, because ITS IN LAND!
Solution, set all these civilian land buildings on IslandBuilding

Now "Bride Destroyed":
-same thing as above really, the stone bridge GUID, or in fact ALL BRIDES GUIDs are as follows:
stone bridge:
template BridgeBuilding:
and then they likely refer back to the properties.xml which says for Standard: Ship
Solution: set all these bridges on [NONE] in their asset GUIDs

Yes ladies and gentlemen, we have land buildings set as harbor buildings and bridges set as ships... (I swear, who at Ubisoft is responsible for this?)

How did I find this? Well by poking around of course, which should be Ubisoft's job, not mine, they have been getting reports about this for months now ever since GU15, and instead of fixing these issues first they just went on to GU16 but havnt even fixed issues from before yet, not cool at all...

So the basics:

in assets.xml: 
HarbourBuilding
IslandBuilding
[NONE]
in properties.xml (default values):
Ship
in templates.xml:
Airship


and now I'm going to copy paste my own experimentation: (its crude, but it explains what I did step by step to lead to this conclusion)

ships never seem to have an , this leads me to conclude they fall back on the properties.xml which says Standard = Ship
so perhaps buildings missing this will also be categorized as a ship
either way, we have seen land buildings with "HarbourBuilding", land buildings which do not even have an , even their templates do not have this mentioned meaning I would have to add it to their templates as well cause if I only add it to the asset itself then CTD will happen.
I'm going to put my own AI artillery cannon on "IslandBuilding", then on "NONE" and see if I can still attack it or not, and from there perhaps test some other things
AI Artillery=IslandBuilding, so I cannot command my ship to directly attack the AI artillery, moving closer to see if it shoots automatically, ship refused to shoot it on its own
shooting mortar on AI artillery does no dmg
dropping airbombs on AI artillery does no dmg
my ships were shooting the nearby stone road bridge instead, wth?
Ive noticed this before many times that I got messages "your building has been destroyed" and it pointed me to bridges, now I know why.
I can even command my ships to attack bridges
I need to look up the GUID of stone bridge and see whats in there, why the heck are my ships shooting it
stone bridge:
template BridgeBuilding:
might fall back on properties.xml and label it as a ship
since it has the tag, im gonna edit it and make it [NONE] 
I think I found an easy way to find which buildings are bugging AI ships
take your own ship, hover with mouse over AI buildings u are at war with, which buildings have the "attack icon"? 
old world: fire station, police station, hospital, wooden bridge, stone bridge 
putting AI artillery to [NONE] had same effect as "IslandBuilding", could not attack it, nor does bombing it do any dmg
maybe IsLandBuilding makes it destructable by fires and such while [NONE] does not???
put Stone Bridge to [NONE], ships no longer attack it
hovering with mouse over Cattle Farm Fields does not show "attack" icon, wandering why AIs destroy those fields then...
Instead of editing the bridge asset to [NONE] I'm going to remove it instead and see what happens
Removing from Stone Bridge had no effect, falls back on its template, then on properties.xml, ships will still attack it
so it HAS to be edited to become [NONE]
or Id have to edit the templates.xml as well perhaps, ugh
well I think we can conclude whats causing AI ships being stuck now, how to fix it, but it will require extensive editing on many buildings and even their templates to get it fully fixed
though one thing still unknown is the farm fields, why AI attack those since they have no tag at all, neither do their template


Bottom line, you have bridges with the tag being empty and pointing back to the properties.xml, which likely makes the bridges be like ships.
And you also have many Land Buildings like Police Stations, Fire Stations and Hospitals all set as Harbor Buildings, causing AI ships to get stuck on the shores.
And you have many buildings which have no tag on the asset or on their template, who knows what issues that causes?
And lastly, we have those farm fields which I don't even understand why or how the AI attacks them since again they have no tag at all...
Perhaps the solution to farm fields being attacked by AIs would be to simply add the following to the "Farmfield" template, which I believe is used by all farm fields:


    [NONE]

and then add  to each and every farm field asset GUID, then the farm fields will likely not be attackable anymore.

I hope this information which directly points you to the source of the issue is enough for you to fix all these bugs asap.
And please, I beg of you, hire some decent people to add these kinds of changes into the game next time, this entire thing reeks of either laziness or complete incompetence.
Please re-check all the and on all buildings, farm fields and bridges and ensure no AI will attempt to go to any building/field/bridge on land, which obviously causes their ships to get stuck on the shores.

plus did I mention I absolutely hate how I constantly have to rebuild farm fields because AIs always shoot it, it adds no value to the game, its just annoying, and likely a bug to begin with.

I hope I will get a reply to this from Ubisoft and that these bugs will finally get fixed in the near future, otherwise I'm just wasting my time on this forum.

over 1 year ago - Ubi-Thrupney - Direct link

Hey @IIAc3sII - sincerest apologies for the slow response, and thanks so much for this write-up. Fortunately, I can see our teams are aware of what's causing this issue, so I'm confident they're doing everything they can to move the issue along. It does sound like a huge faff to deal with, for sure, so I can understand your frustration. I'd recommend keeping an eye on our News & Announcements forum for updates on this issue!