'ArialMT_Plain_16' was not declared in this scope

I`m trying to compile a code using esp8266 and SSD1306.
And I use Adafruit_SSD1306.h library, but I get this error message

Whole code

#include <Arduino.h>
#include <ESP8266WiFi.h>
#include <ArduinoJson.h>
#include <ESP8266HTTPClient.h>
#include <WiFiClient.h>

#include <Adafruit_SSD1306.h>
#include <Adafruit_GFX.h>
#include <splash.h>

#include <Wire.h>

#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels

#define OLED_RESET -1 // Reset pin # (or -1 if sharing Arduino reset pin)
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

char* ssid = "e-Broad690vb3th";
const char* password = "422e6a59d2";

const String endpoint = "http://api.openweathermap.org/data/2.5/weather?q=chiba,jp&APPID=";
const String key = "e8b6ba7b9f80d5870b70b44a9c08da2d";

void setup() {
Serial.begin(115200);
display.clearDisplay();

WiFi.begin(ssid, password);

while (WiFi.status() != WL_CONNECTED) {
delay(1000);
Serial.println("Connecting to WiFi..");
}
Serial.println("Connected to the WiFi network");

}

void loop() {
if ((WiFi.status() == WL_CONNECTED)) {
WiFiClient client;
HTTPClient http;
http.begin(client, endpoint + key); //URLを指定
int httpCode = http.GET(); //GETリクエストを送信

if (httpCode > 0) { //返答がある場合

  String payload = http.getString();  //返答(JSON形式)を取得
  Serial.println(httpCode);
  Serial.println(payload);

  //jsonオブジェクトの作成
  DynamicJsonBuffer jsonBuffer;
  String json = payload;
  JsonObject& weatherdata = jsonBuffer.parseObject(json);

//パースが成功したかどうかを確認
if (!weatherdata.success()) {
  Serial.println("parseObject() failed");
}

//各データを抜き出し
const char* weather = weatherdata["weather"][0]["main"].as<char*>();
const double temp = weatherdata["main"]["temp"].as<double>();

//LCDに表示
display.clearDisplay();//画面を消去
//天気を表示
display.setFont(ArialMT_Plain_16);
display.drawString(0, 0, weather);
//気温を表示
display.setFont(ArialMT_Plain_24);
String temp_str = String(temp - 273.15) + "°C";
display.drawString(20, 20, temp_str);
display.display();

}

else {
Serial.println("Error on HTTP request");
}

http.endRequest(); //Free the resources
}

delay(30000); //30秒おきに更新

}

@rabbit787, your topic has been moved to a more suitable location on the forum. Installation and Troubleshooting is not for problems with (nor for advise on) your project :wink: See About the Installation & Troubleshooting category.

Please edit your post, select all code and click the </> button to apply so-called code tags and next save your post. It makes it easier to read, easier to copy and prevents the forum software from incorrect interpretation of the code.