When copying the text on the process builder, the system says "The element has an invalid reference to "Communication.Direction__c".", why is that ?  : 

Hey, it’s your friendly rover real estate agent here. Today I'm doing some serious {![Communication__c].Verb__c} over to an area on lower Mount Sharp, heading {![Communication__c].Direction__c} from my starting location. Since the dune field is an active sand field, it is this Rover's guess that the terrain is {![Communication__c].Adjective__c} and therefore unsuitable for the Trailblazer basecamp. You know what they say, “Location, location, location.” I will make my final stop for the day at the super {![Communication__c].Adjective__c} bedrock at the base of Mount Sharp. Roger, Rover. Rover out. P.S. Tell {![Communication__c].Proper_Noun__c} I said hi.

When copying the text on the process builder, the system says "The element has an invalid reference to "Communication.Direction__c".", why is that ?  : 

Hey, it’s your friendly rover real estate agent here. Today I'm doing some serious {![Communication__c].Verb__c} over to an area on lower Mount Sharp, heading {![Communication__c].Direction__c} from my starting location. Since the dune field is an active sand field, it is this Rover's guess that the terrain is {![Communication__c].Adjective__c} and therefore unsuitable for the Trailblazer basecamp. You know what they say, “Location, location, location.” I will make my final stop for the day at the super {![Communication__c].Adjective__c} bedrock at the base of Mount Sharp. Roger, Rover. Rover out. P.S. Tell {![Communication__c].Proper_Noun__c} I said hi.