improvements disappeared

something weird just happened in my mod, all my modded improvements have disappeared my workers will build them but no model appear once built, the strange thing is yesterday would appear but..... anyone run it this problem before

OK after alot of trial and erroring the only thing that working was the last resort dump of the
ModUserData wouldn't recommend it except as a last resort

If you are adding new Art_Defines for the improvements instead of re-cycling the Firaxis-made ones, make sure you have ticked the 'Reload Landmark System' checkbox.