diff --git a/src/ITAGeo/Base.cpp b/src/ITAGeo/Base.cpp
index 1770038e9ab45230964c7d9f7334810cc09aa642..84f12b8a6ceae88398e2513a4f2c9e993e5ec7ed 100644
--- a/src/ITAGeo/Base.cpp
+++ b/src/ITAGeo/Base.cpp
@@ -195,9 +195,12 @@ void ITAGeo::CEmitter::LoadFromJSONString( const std::string& sContent, std::sha
 	//Set the orientation
 	qOrient.SetValues( dOrientation );
 
-	std::string sDirectivityID = jnRoot.at( "directivity_id" ).as_string();
-	if( pResourceManager && pResourceManager->HasDirectivity( sDirectivityID ) )
-		pDirectivity = pResourceManager->GetDirectivity( sDirectivityID );
+	if( jnRoot.find( "directivity_id" ) != jnRoot.end() )
+	{
+		std::string sDirectivityID = jnRoot.at( "directivity_id" ).as_string();
+		if( pResourceManager && pResourceManager->HasDirectivity( sDirectivityID ) )
+			pDirectivity = pResourceManager->GetDirectivity( sDirectivityID );
+	}
 #endif
 }
 
@@ -304,9 +307,13 @@ void ITAGeo::CSensor::LoadFromJSONString( const std::string& sContent, std::shar
 	//Set the orientation
 	qOrient.SetValues( dOrientation );
 
-	std::string sDirectivityID = ( std::string ) jnRoot.at( "directivity_id" ).as_string();
-	if( pResourceManager->HasDirectivity( sDirectivityID ) )
-		pDirectivity = pResourceManager->GetDirectivity( sDirectivityID );
+
+	if( jnRoot.find( "directivity_id" ) != jnRoot.end() )
+	{
+		std::string sDirectivityID = ( std::string ) jnRoot.at( "directivity_id" ).as_string();
+		if( pResourceManager->HasDirectivity( sDirectivityID ) )
+			pDirectivity = pResourceManager->GetDirectivity( sDirectivityID );
+	}
 #endif
 }