I noticed that a mod setting is missing

  36.256 Loading mod kry-vehicle-grids 2.1.27 (data-final-fixes.lua)
  36.265 Error ModManager.cpp:1767: Fehler beim Laden der Mod „kry-vehicle-grids“: __kry-vehicle-grids__/prototypes/mod-final-fixes.lua:93: attempt to index field 'hovercraft-grid' (a nil value)
stack traceback:
    __kry-vehicle-grids__/prototypes/mod-final-fixes.lua:93: in main chunk
    [C]: in function 'require'
    __kry-vehicle-grids__/data-final-fixes.lua:8: in main chunk

Adding this to the settings.lua fixed the issue:

if mods["Hovercrafts"] then
    local new_settings = {
        {
            type = "bool-setting",
            name = "hovercraft-grid",
            setting_type = "startup",
            default_value = true,
            order = "a-e-c"
        },
    }
    Table.merge(krygridtable,new_settings,true)
end

You might have mis-diagnosed the problem here; it's not missing from my end, but rather removed from the Hovercrafts mod (which I just never noticed; that update was made back in November.. of 2024, as in over a year ago).

The additional hovercrafts now always have their own equipment grids defined, rather than being toggleable via mod setting, so this entire block of compatibility code is no longer necessary.

Should be fixed in v2.1.29

hm, I see. Thanks for the fix anyway :D