Improve error messages for better user experience

lib/ably/models/message_encoders/cipher.rb

@@ -25,10 +25,12 @@ def encode(message, channel_options)
         add_encoding_to_message "#{ENCODING_ID}+#{crypto.cipher_params.cipher_type.downcase}", message
       end
     rescue ArgumentError => e
-      raise Ably::Exceptions::CipherError.new(e.message, nil, 92005)
+      # ably-os:inline-error-update:92005:2025-08-22:e8u Original: "#{e.message}"
+      raise Ably::Exceptions::CipherError.new("Encryption failed due to configuration error: #{e.message}. Check your cipher key format and message data", nil, 92005)
     rescue RuntimeError => e
       if e.message.match(/unsupported cipher algorithm/i)
-        raise Ably::Exceptions::CipherError.new(e.message, nil, 92004)
+        # ably-os:inline-error-update:92004:2025-08-22:e8u Original: "#{e.message}"
+        raise Ably::Exceptions::CipherError.new("Unsupported cipher algorithm specified. #{e.message}. Supported algorithms: AES-128-CBC, AES-256-CBC", nil, 92004)
       else
         raise e
       end

lib/ably/modules/conversions.rb

@@ -113,7 +113,8 @@ def ensure_supported_payload(payload)
         payload.kind_of?(Array) ||
         payload.nil?
 
-      raise Ably::Exceptions::UnsupportedDataType.new('Invalid data payload', 400, Ably::Exceptions::Codes::INVALID_MESSAGE_DATA_OR_ENCODING)
+      # ably-os:inline-error-update:40013:2025-08-22:e8u Original: "Invalid data payload"
+      raise Ably::Exceptions::UnsupportedDataType.new("Invalid data payload: #{payload.class} is not supported. Use String, Hash, Array, or nil", 400, Ably::Exceptions::Codes::INVALID_MESSAGE_DATA_OR_ENCODING)
     end
 
     # Converts the name, data, attributes into the array of Message objects

lib/ably/realtime/client/incoming_message_dispatcher.rb

@@ -141,7 +141,8 @@ def dispatch_protocol_message(*args)
             client.auth.authorize
 
           else
-            error = Ably::Exceptions::ProtocolError.new("Protocol Message Action #{protocol_message.action} is unsupported by this MessageDispatcher", 400, Ably::Exceptions::Codes::PROTOCOL_ERROR)
+            # ably-os:inline-error-update:80013:2025-08-22:e8u Original: "Protocol Message Action #{protocol_message.action} is unsupported by this MessageDispatcher"
+            error = Ably::Exceptions::ProtocolError.new("Protocol error: unsupported action '#{protocol_message.action}' received. Check your SDK version and protocol compatibility", 400, Ably::Exceptions::Codes::PROTOCOL_ERROR)
             logger.fatal error.message
         end
       end

lib/ably/realtime/presence.rb

@@ -349,7 +349,8 @@ def sync_complete?
     def send_presence_protocol_message(presence_action, client_id, data, id = nil)
       presence_message = create_presence_message(presence_action, client_id, data, id)
       unless presence_message.client_id
-        raise Ably::Exceptions::Standard.new('Unable to enter create presence message without a client_id', 400, Ably::Exceptions::Codes::UNABLE_TO_ENTER_PRESENCE_CHANNEL_NO_CLIENTID)
+        # ably-os:inline-error-update:91000:2025-08-22:e8u Original: "Unable to enter create presence message without a client_id"
+        raise Ably::Exceptions::Standard.new('Unable to enter presence channel without a client_id', 400, Ably::Exceptions::Codes::UNABLE_TO_ENTER_PRESENCE_CHANNEL_NO_CLIENTID)
       end
 
       protocol_message = {