I play with SE. When I enter navius orbit I see this error. Everything is updated. Also installed gui unifier. It didnt help. And navius is the only planet with cannons.

Error while running event Kux-OrbitalIonCannon::on_nth_tick(60)
Kux-CoreLib/lib/InitGlobals.lua:161: Invalid input: "Nauvis"
stack traceback:
[C]: in function 'error'
Kux-CoreLib/lib/InitGlobals.lua:161: in function <Kux-CoreLib/lib/InitGlobals.lua:120>
(...tail calls...)
Kux-OrbitalIonCannon/modules/IonCannon.lua:15: in function 'getOrbitingSurface'
Kux-OrbitalIonCannon/modules/IonCannon.lua:88: in function 'countOrbitingIonCannons'
Kux-OrbitalIonCannon/modules/gui.lua:292: in function 'update_GUI'
Kux-OrbitalIonCannon/control.lua:138: in function 'fnc'
Kux-CoreLib/lib/EventDistributor.lua:146: in function <Kux-CoreLib/lib/EventDistributor.lua:143>

Same error :(

I have found a temporary fix.

Go into the mod file Kux-OrbitalIonCannon_3.8.14/modules/IonCannon.lua

In there, line 14, you will find this segment:

function IonCannon.getOrbitingSurface(surface)
surface = getSurface(surface)
if surface.platform and surface.platform.space_location and surface.platform.space_location.type=="planet" then
local s = game.surfaces[surface.platform.space_location.name]
if s and s.valid then surface = s end
end
return surface
end

This function only makes sense when you are playing with Space Age, not with Space Exploration, and it is the one causing the crash.

Edit the function to just return the surface, like so:

function IonCannon.getOrbitingSurface(surface)
return surface
end

Save, reboot your game, and everything will now work. Happy blasting!