No need to check for duplicates as they should now be deleted on update.

index.php

@@ -538,32 +538,18 @@ HTML;
 		$message_files = array_slice( $message_files, 0, 1000 ); 
 
 		//	Loop through the messages:
-		//	Remove any which have been updated.
 		//	Ensure messages are in the right order.
 		$messages_ordered = [];
-		$messages_ids = [];
 		foreach ( $message_files as $message_file ) {
-			//	Get the contents of the JSON 
-			$message = json_decode( file_get_contents( $message_file ), true );
+			//	Split the filename
+			$file_parts = explode(".", $message_file );
+			$type = $file_parts[1];
 
 			//	Ignore any messages which aren't for display
-			$type = $message["type"];
-			if ( "Undo" == $type ) { continue; }
+			if ( "Undo" == $type || "Delete" == $type ) { continue; }
 
-			//	Get the ID
-			if ( isset( $message["object"]["id"] ) ) {
-				$id = $message["object"]["id"];
-			} else if ( isset( $message["id"] ) ) {
-				$id = $message["id"];
-			}
-
-			//	Has this message ID already been seen?
-			//	If so, it's an older update. Skip displaying it
-			if ( !in_array( $id, $messages_ids ) ) {
-				$messages_ids[] = $id;
-			} else {
-				continue;
-			}
+			//	Get the contents of the JSON 
+			$message = json_decode( file_get_contents( $message_file ), true );
 
 			//	Sometimes messages are received out of order.
 			//	This sorts them by their published time or, if there is none, the received time.