1) Husky v1.9.3 (f14b)

2) All of them

3) Road to 56, EU4 Ideas, National ideas GUI, Player Led Peace Conferences, State Transfer Tool

4) Basically the problem is that I can't play in multiplayer with my friends. It works fine in SP but if I try to host a game and they try to join... they just can't, they get an error message "Failed to connect" (or something like that), but if I disable this mod and only this mod the server works just fine, they can join and play. Any idea on what could be the problem? We would prefere to play with this mod because it's kinda helpful

Mostly sure that files messed up. Useful for almost ALL cases when smth is missing/red triangle, no updated content
1) Unsub from this mod
2) Delete files in this path (drive should be the same as HoI4 is installed on)
SteamLibrary\steamapps\workshop\content\394360\1835918659
3) Delete file mods_registry.json (or game_data.json) in
Documents\Paradox Interactive\Hearts of Iron IV
4) Exit Steam
5) Enter Steam
6) Subscribe to the mod
If this did not help then your friends should do the same.
If this still did not help download files manually. Check some manual installation guides for HoI IV mods.

About what CanadianJason wrote in the comments. There really is such a thing, try to increase -1.00 to -10.00 or many big (-100% to -1000%) and enter the cost of the battleship into the modifiers (capital_ship = {
instant = yes
build_cost_ic = -10.00
}).
The first is because the value is decreasing rather than becoming negative. Second, the cost of battleships remains default.
Sorry for my bad googletranslate.

Насчет того что писал в коментах CanadianJason. Такое действительно есть, попробуй увеличить -1.00 до -10.00 (-100% до -1000%) и впиши в к модификаторам стоимость линкора
( capital_ship = {
instant = yes
build_cost_ic = -10.00
} ).
Первое - потому что стоимость уменьшается, а не становится отрицательной.
Второе - стоимость линкоров остается дефолтной.
Вторая версия на русском сделана уже после того как зашел на личную страницу в стиме.

Please, use the form in the head of Discussion. As I mentioned before, I was not able to re-create the issue. In my case, if you will point mouse over them - it will tell: next complete - never.

So I've finally got that issue: instant production. I will try make some changes another way or will make values negative.

so let it remain so. for it will not be produced anyway, and the ships will not be removed

Or do you want it to go to zero? you can try to cut the performance of the shipyard

Cutting efficiency will be not the best change tbh. And looking on logistics tab tells me that everything works fine now.

https://sun9-46.userapi.com/ENaHD0wCMSpT5NdQ54L33D3m4mNbubWmmq8R3w/mm-PjMJD2Dk.jpg

battleship lol, (capital_ship)

going back to navy_production_no - rearmament cost = 0, which makes rearmament instant and free
https://sun9-12.userapi.com/qXLijG1QVsPJ3OVKMISvDMAwZJ9TWXL539ImTg/L6Kvw2Yh8lw.jpg

Version: 1.10.8
DLCs: All of the DLC available at time of writing.
Other Mods: R56, Man The Guns: Extended R56 Version, Victoria II Party Policies, and a bunch of others that do no overlap with the affected content.

It seems that the navy_production_no idea does not get removed once you switch it off, so all of my ships were impossible to build until I went through the savegame and manually scrubbed it from each affected design. I think that it might be a better idea to use a dockyard output modifier instead.

I guess that is truly a problem of such approach. But the way this designer (yes, it is actually a ship designer) work is that they are applied to all current ship models and on new researched ships, thus it is impossible to produce old designs until you create a new ship design without that idea.

extremely exploity thing about that navy_production_no thing, if you have other mods active as well, (idk about just the mod) ships basically become instant built, including something like cruisers. A solution would be to give it the effect of turning dockyard output down to basically 0 by granting it a -1000% dockyard output modifier or something. A similar issue does not appear with the similar option for airplanes