Whenever i use the mod subsurface from natha and try to place a turbine on the lower levels, i get the following message:

Error while running event k2-wind-turbine-zars-fork::on_built_entity (ID 6)
k2-wind-turbine-zars-fork/control.lua:23: attempt to index field 'planet' (a nil value)
stack traceback:
k2-wind-turbine-zars-fork/control.lua:23: in function 'update_turbine_parameters'
k2-wind-turbine-zars-fork/control.lua:46: in function 'update_turbine_on_built'
k2-wind-turbine-zars-fork/control.lua:71: in function <k2-wind-turbine-zars-fork/control.lua:70>

Fixed in version 1.2.7!

Wind turbines probably shouldn't work underground at all, but at least the mod won't crash now.

Thank you very much, and well, your right that they shouldnt work underground, but i find it funny to power a base with wind thats underground

I suppose it is funny! XD (And don't worry, I don't have any plans of fixing it.)