Found a fix. Open the mod and go to control.lua, replace line 125 and below with:
script.on_event(defines.events.on_research_finished, function(event)
local research = event.research.name
if string.find(research, "alien%-hybrid%-upgrade") then
update_current_tier(game.forces['player'])
-- I'm still not sure if it's possible to handle multiple player forces with different tiers, but in theory you'd call the force of the one doing the research here, not player.
update_walls()
end
end
)
