entity script adaptation for Creatio 8.1

Hello,

i'm trying to fix a script from an entity event, which used to work before Creatio 8,

i need to compile the entity that hold it but there is an error i can't figure out :

on this line : 

var IsChangedUsrFraisDePortHT = Entity.GetChangedColumnValues().Any(col => col.Name == "UsrFraisDePortHT");

i got that error message after publishing :

'IEnumerable<EntityColumnValue>' does not contain a definition for 'Any' 
and no accessible extension method 'Any' accepting a first argument of type 'IEnumerable<EntityColumnValue>' 
could be found (are you missing a using directive or an assembly reference?)  

how should i process please ?

Best regards

Patrice